Digital Photography Glossary
Struggling with a word or phrase? You're not alone. Photography has long had its own language, and digital photography adds many new terms. This glossary defines commonly used words and phrases in digital photography.
0-9
24-bit image: This type of digital image has pixels that are allocated 24 bits of storage (usually with 8 bits for red, 8 for blue, and 8 for green), allowing representation of 256 by 256 by 256 (or more than 16 million) different color combinations.
3D Color Matrix Meter: Basically, a Nikon pioneered technology first started featured on its flagship model, the F5, will expect more models to include this to fully utilize this. 3D Color Matrix Meter * evaluates not only each scene's brightness and contrast but, using a special Red Green Blue (RGB) sensor, it also evaluates the scene's colors. Then its powerful micro-computer and database together guide it to unequaled exposure control. * Currently, 3D Color Matrix Meter will work only with F5 & with D-type Nikkor lenses, other new Nikon models should roll out to fully utilized this exclusive features.
8-bit image: This is a digital image composed of as many as 256 possible colors or shades of grey.
100 percent crop: a section of a digital image that is cropped before it is reduced in size or edited. Since images are large, a 100% crop lets others see the quality of an image at full resolution without displaying the entire image.
A
Acquire: The act of transferring an image from a digital camera to a computer or of importing it from another source into a program, such as Adobe Photoshop.
ABC: First featured in Contax (am I wrong?). Also sometimes refer as AEB (Auto Exposure Control). Auto Bracketing control: Metering feature that automatically produces three or four different exposures with one press of the shuttle release. Usually one with the recommended exposure by the camera reading, others at user specified intervals above or below the recommended setting.
ABC: Auto Backlighting Control, metering feature that automatically recognizes a subject in back lighting condition and increase the exposure to compensate.
Accessory Shoes: also often called "Hot Shoe". The early flash types were simple metal brackets. To install a flash unit, you just slide the mounting foot of the flash into the accessory shoe. No electrical connection is made between camera and flash - it's just a simple and convenient way to attach the flash unit to the camera. Subsequent accessory shoes have been built as part of the camera and usually resat on top of the camera's pentaprism; others are separate items that you mount on the camera body when you need them. Some like the Nikon early professional camera has special dedicated which was designed around the rewind knob.
Aberration: Failing in the ability of a lens to produce a true image. There are many forms of aberration and the lens designer can often correct some only by allowing others to remain. Generally, the more expensive the lens, the less its aberrations (More attention to optical quality). While no single lens is called a 'perfect lens'. The "ideal" lens would reproduce a subject in a faithful, clearly defined image on film. Aberrations, which can be divided into six basic faults, affect the Ideal performance in an optical system.
a) Spherical aberration. Basically, a beam of light passing through a lens parallel to the optical axis converges to form 3 focused image on the film. Spherical aberration is the term for an optical fault caused by the spherical form of a lens that produces different focus points along the axis for central and marginal rays.
b) Curvature of field. This optical defect causes points on an object plane perpendicular to the lens axis to focus on a curved surface rather than a plane.
c) Astigmatism. Rays of light from a single point of an object which is not on the axis of a lens fail to meet in a single focus thus causing the image of a point to be drawn out into two sharp lines, one radial to the optical axis and another perpendicular to this line, in two different planes near the curvature of field.
d) Coma. This optical defect causes the image of an off-axis point of light to appear as a comet-shaped blur of light. Coma, as well as curvature of field and astigmatism, degenerate the image forming ability of the lens at the rims of the picture.
e) Distortion. Even if the first four aberrations were totally eliminated, images could result that still have a distorted appearance. For an example, an rectangle may appear as a barrel or pin cushion-shaped object.
f) Chromatic aberration. This aberration is caused by light rays of different wavelengths coming to focus at different distances from the lens. Blue will focus at the shortest distance and red at the greatest distance. Since the natural rays of light are a mixture of colors, each aberration will give a different value corresponding to each color thus producing blurred images.
Adaptive palette: This is a set of colors selected to represent, as closely as possible, the colors in the original source image.
Adjustable Camera: Commonly called the manual camera. A camera with manually adjustable settings for distance, lens openings, and shutter speeds. eg Nikon FM series, Carl Zeiss S2, Pentax K1000, Yashica FX-3 super etc.
Adjustable-Focus Lens: A lens that has adjustable distance settings.
Advanced Photo System: A new standard in consumer photography developed by Kodak and four other System Developing Companies - Canon, Fuji, Minolta and Nikon - based on a new film format and innovative film, camera and photofinishing technologies. Generally, APS cameras are more compact in size, weight and embodied most of the latest and most advance technologies available. There are options in various sizes of print out and it will even provide a thumbnail prints (Contact sheet) for you to select or preview prior to actual printing. There have a different series of lenses and some of the 35mm format AF lenses can even be shared (With limitation or effective focal length will increased). You can say, it is a different system camera all together. So much for the brighter side, but there are drawbacks as well and it is not that economical as I originally thought it supposed to be.
AE: (Automatic Exposure)
AE-L (Automatic Exposure Lock): Auto exposure Lock. Metering feature that used to hold the exposure setting when used in the automatic mode. Used most commonly in situation where off centering of the subject in composition and wish to retain the exposure setting of the subject OR where the level of exposure reading both the subject of interest and the background exposure reading is different eg. back lighting. Used to hold an automatically controlled shutter speed and/or aperture. Recommended when the photographer wants to control an exposure based on a scene's particular brightness area with Center Weighted or Spot Metering.
AF: Auto-focus systems often include an AF lamp that helps the system focus in low light situations. The lamp may use visible or infrared light.
AF sensor: The sensor used to detect and help correct the focus in cameras equipped with an autofocus function.
Agitation: Keeping the developer, stop bath, or fixer in a gentle, uniform motion while processing film or paper. Agitation helps to speed and achieve even development and prevent spotting or staining.
Algorithm: A formula or set of steps for solving a particular problem.
Alphabetical Coding: Some early lenses such as Nikon and Olympus uses some alphabetical coding to illustrate the composition of their lenses. For an example, each ZUIKO Lens is described with an alphabetical prefix and suffix such as F . ZUlK0 AUTO-S, AUTO-T, etc. The prefix represents the number of elements in a lens in alphabetical order. For an instance, "A"=1 element, "B"=2 elements, "D"=4 elements, and so forth. "AUTO" signifies automatic diaphragm. The suffix represents the type of lens: "S": Standard, "W"=Wide Angle and "T"=Telephoto. While another example:
U (Uns) for 1 lens element
B (Bini) for 2 elements
T (Tres) for 3 elements
Q (Quatour) for 4 elements
P (Pente) for 5 elements
H (Hex) for 6 elements
S (Septem) for 7 elements
0 (Octo) for 8 elements
N (Novem) for 9 elements
D (Decem) for 10 elements
Ambient Light: The available natural light completely surrounding a subject. Light already existing in an indoor or outdoor setting that is not caused by any illumination supplied by the photographer i.e. not by artificial light source.
Ambient: A term used to describe the lighting or illumination in a scene that does not originate from any specific light source, direction, or object in the scene.
Angle of view: The width of the area a lens can see; measured in degrees.
Angle Of View: The area of a scene that a lens covers or sees. Angle of view is determined by the focal length of the lens. A wide-angle lens (short-focal-length) includes more of the scene-a wider angle of view-than a normal (normal-focal-length) or telephoto (long-focal-length) lens. Currently, the widest view available is 220 degree (achieved by Nikon's Nikkor 6mm F2.8 fisheye lens - 220 degree; while the narrowest is Nikon, 2000mm F11 Reflex Nikkor, only slightly over 1 degree of view. It can also be explained as the extent of the view taken in by a lens. For any particular film size, it varies with the focal length of the lens. Usually expressed on the diagonal of the image area. Basically, there are three types of angles which can be measured (based on horizontal, vertical and diagonals of the film frame), the lens must be designed to cover the widest angle in the diagonal direction. Thus, the angle of view is the angle between imaginary lines drawn from the opposite ends of the film plane to the second nodal point of the lens. All objects within this angle will be recorded by the lens on the film.
A-PEN: Annealed polyethylene naphthalate-a polyester material used as the base on Advanced Photo System film; thinner, stronger and flatter than the acetate base traditionally used in consumer photographic roll films.
APO: Apochromatic. Having the ability to bring all colors of the visible spectrum to a common plane of focus, within close tolerances, usually refer to a lens with such superior color correction. Also refer to "ED", "LD", "SD", "UD".
APS: (Advanced Photo System): Often called APS-C (for classic). Format first developed for film (for example, with the Kodak Advantix system) and is now used by most manufacturers as their reference for sensor size. There are slight variations in actual size between some manufacturers.
Archival: The ability of a material, including some printing papers and compact discs, to last for many years.
Aperture: A small, circular opening inside the lens that can change in diameter to control the amount of light reaching the camera's sensor as a picture is taken. The aperture diameter is expressed in f-stops; the lower the number, the larger the aperture. For instance, the aperture opening when set to f/2.8 is larger than at f/8. The aperture and shutter speed together control the total amount of light reaching the sensor. A larger aperture passes more light through to the sensor. Many cameras have an aperture priority mode that allows you to adjust the aperture to your own liking. See also shutter speed.
Aperture priority: a function of a semi-automatic camera that permits the photographer to preset the aperture and leaves the camera to automatically determine the correct shutter speed.
Aperture Priority: An exposure mode on an automatic or autofocus camera that lets you set the aperture while the camera sets the shutter speed for proper exposure. If you change the aperture, or the light level changes, the shutter speed changes automatically. Apart from the sport or action arena, aperture priority is the most common & effective automatic preference in photography. It can also explained as automatic exposure system in which the lens aperture is set by the photographer, and the camera sets the shutter speed. Can be used in the stop-down mode with any lens that does not interfere with the metering system.
Aperture ring: A ring, located on the outside of the lens usually behind the focusing ring, which is linked mechanically to the diaphragm to control the size of the aperture; it is engraved with a set of numbers called f-numbers or f- stops.
Application: A computer program, such as an image editor or image browser.
Artifact: Misinterpreted information from a JPEG or a similarly compressed image; includes defects that appear in an image as color flaws or skewed lines.
Artificial light: Light from a man-made source, usually restricted to studio photo lamps and domestic lighting.
ASA: American Standards Association. Group that determining numerical ratings of speed for US made photosensitive products. eg films. In 1982, its role and its influence was narrow down by the establishment of the ISO (International Standards Organization).
Aspect ratio: While most point-and-shoot cameras offer an aspect ratio of 4:3 (the equivalent of a regular television or computer screen), most DSLR sensors have an aspect ratio of 3:2 (the equivalent of a standard 4x6 inches picture). The two numbers of the aspect ratio simply represent the relative lengths of the longest and shortest sides of the image rectangle.
Aspect Ratio: The ratio of width to height in photographic prints - 2:3 in 35 mm pictures to produce photographs most commonly measuring 3.5 x 5 inches or 4 x 6 inches; Advanced Photo System cameras deliver three aspect ratios as selected by the user.
ATA: This means the camera supports the electrical interface standard, defined by the PC Card Association (formerly PCMCIA), known as ATA (AT Attachment). This is the mobile computing equivalent of the IDE standard for desktop computers. Most computers have ATA support built-in. ATA is supported by most operating systems like Microsoft Windows 3.1, Windows '95, Windows CE, IBM OS/2, Apple System 7, etc. ATA is supported by most computer manufacturers including IBM, Compaq, Packard Bell, Dell, Gateway 2000, etc.
Aspherical lens: A lens whose curved surface does not conform to the shape of a sphere; lenses are usually ground or molded with spherical surfaces; because a spherical surface lens has difficulty in correcting distortion in ultra-wideangle lenses or coma in large-aperture lenses brought about by spherical aberration, an aspherical lens is used.
ASCII: American Standard Code for Information Interchange (ASCII) is an ANSI binary-coding scheme consisting of 128 seven-bit patterns for printable characters and control of equipment functions. ASCII is the basis for information exchange between many computer systems.
Auto Exposure Bracketing: Auto Exposure Bracketing performs automatic exposure bracketing with varied shutter speed and/or aperture.
Autofocus (AF): System by which the camera lens (most popular) or the camera body (only available in Contax AX) automatically focuses the image of a selected part of the picture subject. The autofocus camera revolution first popularized with the launch of Minolta's Maxxium. Currently, most current SLRs are autofocus based.
AF-I & AF-S lenses: Nikon's new series of AF lenses, involves the intergration of coreless motors into their super telephoto lenses. This gives these lenses quick, ultra quiet autofocus operations. While the AF-S lenses housing a silent wave motor for even quicker and quiet operations than the AF-I lenses, which was being in the stage of being replaced by the newer series.
Autofocus: Camera feature that uses an infrared (IR) beam or sonar to set its focus.
Automatic Camera: A camera with a built-in exposure meter that automatically adjusts the lens opening, shutter speed, or both (program) for proper exposure.
Automatic exposure: a mode of camera operation in which the camera automatically adjusts the aperture, shutter speed, or both for proper exposure.
Automatic iris: Lens diaphragm which is controlled by a mechanism in the camera body coupled to the shutter release. The diaphragm closes to any preset value before the shutter opens and returns to the fully open position when the shutter closes.
Available light: The light present in an area without the addition of a strobe or a floodlight.
AV: The Aperture value, usually refer to aperture settings.
AVI: Short forAudio Video Interleave; the file format for Microsoft's Video for Windows standard, one of several video technologies used on personal computers. (Others include MPEG, RealMedia, and QuickTime.) In AVI, picture and sound elements are stored in alternate interleaved chunks in the file so that they play in sync
B.
B (Bulb) Setting: A shutter-speed setting on an adjustable camera that allows for time exposures. When set on B, the shutter will stay open as long as the shutter release button remains depressed. Another similar option is the "T" setting, where it never drains the battery power on automatic camera body.
Background: The part of the scene the appears behind the principal subject of the picture. The sharpness of the background can be influenced by apertures and shuttle set. In the flash mode, bulb setting usually is set for absorbing more ambience light (background information), so the end result of the exposure won't be pitch dark.
Backlighting: Light coming from behind the subject, toward the camera lens, so that the subject stands out vividly against the background. Sometimes produces a silhouette effect. Always use something (a hand, a lens shade to avoid the light falls onto the lens - to avoid lens flares).
Back-Printing: Information printed on the back of a picture by the photofinisher. The system standard requires the printing of frame number, film cassette number and processing date automatically on the back of each Advanced Photo System print; may also include more detailed information, such as customized titles and time and date of picture-taking.
Balance: Placement of colors, light and dark masses, or large and small objects in a picture to create harmony and equilibrium. Description applied to color films to indicate their ability to produce acceptable color response in various types of lighting. The films normally available are balanced for daylight (550~6000K photo lamps (3400K) or studio lamps (3200K).
Balanced Fill-Flash: A type of TTL auto flash operation which uses the camera's exposure meter to control ambient light exposure settings, integrated with flash exposure control. That is, flash output level is automatically compensated to balance with ambient light, resulting in a better exposure for both subject and background.
Balanced fill-flash operation: A flash photography technique that balances flash illumination with the scene's ambient light. This automatic operation utilizes the some camera's Automatic Balanced Fill Flash System with TTL Multi Sensor and a compatible dedicated TTL Speedlight.
Bas-relief: In digital photography, this refers to an effect produced with a Photoshop filter, which makes an image appear to be slightly raised off the surface.
Barrel distortion: Image distortion produced when the position of the camera lens is at its widest angle. Lines you expect to appear perpendicular are not. It is most noticeable when you have a straight edge near the side of the frame, such as when taking a wide angle shot of a building. Barrel distortion causes the edges of an image to look curved or at a skewed angle. Most barrel distortion can be corrected using image editing software.
Bellows: The folding (accordion) portion in some cameras that connects the lens to the camera body (like the Mamiya RZ). Also a camera accessory that, when inserted between lens and camera body, extends the lens-to-film distance for close focusing or macro photography. Some retains the automatic functions where some have to stop down the lens for manual exposure reading.
Between-The-Lens Shutter: A shutter whose blades operate between two elements of the lens. Most medium format cameras like the Hasselblad have one family of lens with shuttle and another without. Most lenses in this family have a smaller maximum aperture than the other family.
Bit: Short for binary digit, which is a computer value of zero or one, on or off; this is the most basic language used by computers.
Bit depth: Refers to the color or grayscale of an individual pixel. A pixel with 8 bits per color produces a 24-bit image; 8 bits multiplied by three colors -- red, green, and blue -- equals 24 bits. CCDs are colored in a pixel-by-pixel method, using the following guidelines:
* 32-bit color (true color) contains billions of colors; suitable only for high-end use
* 24-bit color (true color) contains 16.7 million colors
* 16-bit color (high color) has 32,000 colors; the accepted standard for Macintosh
* 8-bit color has 256 colors; this is the basic setting for Windows
* 8-bit grayscale has 256 shades of gray
* 4-bit is 64 colors or grays
* 2-bit is black and white
Bitmap: The method of storing information that maps an image pixel, bit by bit. There are many bitmapped file formats, .bmp, .pcx, .pict, .pict-2, tiff, .tif, .gif (89a), and so on. Most image files are bit mapped. This type of file gives you the ´jaggies´, when examined closely you can see the line of pixels that create edges. Bitmap images are used by all computers. The desktop or screen information for all Windows machines uses .bmp files, while the Macintosh uses pict files.
Black point: This is the color that produces color values of 0, 0, 0 for each of the RGB components when scanned or digitized. Normally, the black point is 0 percent neutral reflectance or transmittance.
Bleed: Refers to printing that extends beyond the edge of a page so that the ink meets the edge after the page is trimmed.
blowup An enlargement of a picture; or the process of enlarging a picture (to blow up).
Blowup: An enlargement; a print that is made larger than the negative or slide.
Blur: A photographic effect, either intentional or unintentional, that produces an picture with a loss of image sharpness.
Bmp file: A Microsoft Windows bitmap graphics file that has the extension .bmp.
Body: The camera minus the lens. The body contains the sensor, batteries, processor, controls and user interface.
Bottom Weighted: Refers to the area of the picture that the camera will meter for exposure. When making an auto exposure the camera is programmed to look at a number of spots in the scene, and if the camera was designed to use bottom weighted metering, most of those spots will be in the lower half of the picture.
Bounce light: Light that is bounced off a reflective surface, such as any of the following: a white card, an aluminized reflector, a wall, or the ceiling.
Box camera: Simple camera consisting of a lens, a shutter, a media holder, and a viewfinder.
Bracket flash: Often called handle mount flash. It comprised of one arm of the L-shaped bracket extends under the camera body and uses the camera's tripod socket to mount the camera on the bracket. The vertical arm of the bracket serves as a handle and mounts a flash unit in an accessory shoe often on top of the handle portion, but there are other methods. Flash mounted in a bracket usually requires a separate electrical cord to make the electrical connection between camera body and flash unit.
Bracketing: Take several shots of the same scene at different exposure settings to help ensure getting at least one well-exposed photo; bracket in difficult lighting situations. Some digital cameras have automatic bracketing (see exposure compensation).
Buffer: Memory in the camera that stores digital photos before they are written to the memory card.
BULB Photography: This term refers to a standard setting for slow shutter control. This is a special setting for low light situations, similar to the Shutter Priority Mode. Timing for the shutter is set in the Menu options. The shutter remains open for a longer period of time and the Flash is disabled to capture more of the natural light. Although this is effective, it is not as sophisticated or precise as Shutter Priority.
Burn in: To darken a small area of a picture; named after the process done in a darkroom, where all but the affected area is masked in order to give extra exposure to only the unmasked area.
Burning-In: Basically, a darkroom process that gives additional exposure to part of the image projected on an enlarger easel to make that area of the print darker. This is accomplished after the basic exposure by extending the exposure time to allow additional image-forming light to strike the areas in the print you want to darken while holding back the image-forming light from the rest of the image. Sometimes called printing-in.
Bulb: Flashbulbs - A special flashbulb that can be used at certain shutter speeds is called "FP" where the initials stand for Focal Plane. Designed for use with focal-plane shutters these bulbs make a nearly uniform amount of light for a relatively long time. The idea is to turn on the light before the focal-plane shutter starts to open and keep the light on until the shutter is completely closed. Firing delay for flashbulbs is indicated by code letters: "F"- fast; "M"- medium; "MF" - medium fast; "S" - slow
Byte: Short for binary term; a unit of storage capable of holding a single character; on almost all modern computers, a byte is equal to eight bits.
C
Camera Angles: Various positions of the camera (high, medium, or low; and left, right, or straight on) with respect to the subject, each giving a different viewpoint, perspective or visual effect.
Camera shake: Caused by even a slight movement of the camera as it records an image. Camera shake is the main cause of blurred images.
Candid Pictures: Unposed pictures of people, often taken without the subject's knowledge. These usually appear more natural and relaxed than posed pictures.
Capacitor: Electrical component once more commonly known as a condenser. Stores electrical energy supplied by a power source and can discharge it more rapidly than the source itself. Used in flash equipment, providing reliable bulb firing even from weak batteries, and supplying the surge needed for electronic flash tubes.
Card: Memory chip that can be used to store images and data. Various forms currently exist, the most popular of which is Secure Digital (SD). Other formats include Secure Digital High Capacity (SCHC), Compact Flash, Sony Memory Stick and xD-Picture Card.
Cast: Abnormal coloring of an image produced by departure from recommended exposure or processing conditions with a transparency film, or when making a color print. Can also be caused by reflection within the subject as from a hat on to the face.
Catchlight: A light placed so as to reflect tiny white dots in the eyes of a portrait subject.
CCD: Short for charged coupled device; a mechanism that converts light into a proportional (analog) electrical current; the two main types of CCD are linear arrays, used in flatbed scanners and digital copiers, and area arrays, found in camcorders, digital cameras, and the like.
CCD: Charge Coupled Device: one of the two main types of image sensors used in digital cameras. When a picture is taken, the CCD is struck by light coming through the camera's lens. Each of the thousands or millions of tiny pixels that make up the CCD convert this light into electrons. The number of electrons, usually described as the pixel's accumulated charge, is measured, then converted to a digital value. This last step occurs outside the CCD, in a camera component called an analog-to-digital converter.
CCITT Group III: Data compressed in one dimension yielding an average data reduction of about 5:1 or 6:1. The most common implementation of CCITT Group III is the data reduction circuit found in FAX machines. This technique is also known as "run length encoded."
CCITT Group IV: Compression in two dimensions yielding an average data reduction of 25:1 or better. CCITT Group IV compression requires the execution of 80-million bit oriented operations. The resulting compressed file is roughly the same size as a vector file consisting of graphics.
CD-R – CD-Recordable: a compact disc that holds either 650 or 700 MB of digital information, including digital photos. Creating one is commonly referred to as burning a CD. A CD-R disc can only be written to once, and is an ideal storage medium for original digital photos.
CD-RW – CD-Rewritable: similar in virtually all respects to a CD-R, except that a CD-RW disc can be written and erased many times. This makes them best suited to many backup tasks, but not for long term storage of original digital photos.
Cds: Cadmium Sulfide (Cell). A battery powered, current-modulating. light-sensing cell that was quite popular with lots of cameras exposure metering system and external metering devices. May be this extra will help, photo conductive material used in exposure meters as alternative to selenium-based or silicon blue photocells. Its electrical resistance decreases as the light falling on it increases. Cds meters use current from an external power source, such as a battery.
Center Weighted: Refers to the area of the pictue that the camera will meter for exposure. When making an auto exposure the camera is programmed to look at a number of spots in the scene, and if the camera was designed to use center weighted metering, most of those spots will be in the center area of the picture.
Chromatic aberration: A lens aberration producing an overall blurred image; the inability of a lens to bring all wavelengths of light (especially red and blue) into the same plane of focus; usually present in regular large-aperture telephoto and super-telephoto lenses; does not improve by stopping down the lens; correctable through the use of Iow Dispersion (ED, LD SD) glass. Basically, this aberration is caused by light rays of different wavelengths coming to focus at different distances from the lens. Blue will focus at the shortest distance and red at the greatest distance. Since the natural rays of light are a mixture of colors, each aberration will give a different value corresponding to each color thus producing blurred images.
CI: Contrast Index (sounds like composite index for stock market, ha!) Numeric rating indicating the optimum development contrast for negative materials.
Classic format: one of the three selectable Advanced Photo System print formats; identical to the 2:3 aspect ratio used in 35 mm photography and suitable for most general-purpose shots.
Click stop: Ball bearing and recess or similar construction used to enable shutter speeds, aperture values, etc. to be set by touch.
CGM: Short for computer graphics metafile; this is an image file format designed to handle a wide range of image types.
Chroma: A quality of color, combining hue and saturation.
Chromatic Abberation: Also known as color fringing, this problem is caused when the camera lens do not focus the different wavelengths of light onto the exact same focal plane. It usually happens around subjects with a wide contrast and around the edges of the image in wide-angle shots.
Close-Up: A picture taken with the subject close to the camera-usually less than two or three feet away, but it can be as close as a few inches.
Close-Up Lens: A lens attachment placed in front of a camera lens to permit taking pictures at a closer distance than the camera lens alone will allow.
Close-up lens: Lens that allows close photography; also called a macro lens.
CMYK: Cyan, Magenta, Yellow, Black; These are the printer colors used to create color prints. Most Color Printers, Ink-Jet, Laser, Dye-Sublimation, Thermal, and Crayon printers use these as their printer colors. (This is one of the color management problems for computers. Converting RGB files to CMYK files cause´s color shifts.) When used by a printer the CMYK is also known as a reflective color since it is printed on paper, or reflective films
Codec: Short for compressor/decompressor; a codec is any technology for compressing and decompressing data. Codecs can be implemented in software, hardware, or a combination of both.
color balance Means of compensating for too much of one color in a photo by adding that color's opposite; for example, if a photo has too much blue, adding a larger percentage of yellow would help achieve a balance.
color temperature: A means of measuring the relative redness or blueness of a light source; measured in degrees kelvin (K); higher numbers produce bluer light. Typical incandescent bulbs are approximately 3,200 degrees K, while daylight is about 6,500 degrees K.
color wheel: The circular relationship of all colors based on the frequencies of light at each color.
Compact digital camera: a digital camera that does not take interchangeable lenses (though some take converter lenses). Compact digital cameras range from simple point-and-shoot to ones with advanced settings and manual and semi-automatic control.
Compact Flash: Also known as CF cards, this is the other type of removable memory card. These come in various sizes up to 45mb. The controller is built onto these cards, so as new and faster controllers are designed you can purchase the newer card and take advantage of faster write times. These tend to be a bit more expensive than Smartmedia (SSFDC) cards. Any device that is designed to use a CF card can use any brand of CF cards so long as it meets the CFA (Compact Flash Association) standards (virtually all of them do). There are palmtop computers, voice recorders, and other devices that can use the same cards as your CF compatible camera.
Compression: The reduction of data to reduce the size of a file; compression can be lossy (for example, JPEG images) or lossless (for instance, TIFF images); lossy images have a greatly reduced file size.
Compression Ratio: Compression is a function of the camera's internal programming to take a picture and store in less space than it would normally fill. Virtually all digital cameras save their pictures as JPG (Jay-peg) images because JPG images can be easily compressed. The program in the camera looks at the picture and sees if there are similar pixels in an area., If there are it remembers this and only saves some of them, but uses them to reconstruct the surrounding area of the picture later.
The compression can be of different ratios such as 1:2, 1:4, 1:11, 1:19 and so on (these ratios are sometimes referred to in the camera with terms like Good, Fine, Better, Best, Normal, etc. by the manufacturers). Ratios above about 1:10 are quite high. When the compression is that high, the uncompressed image will have "artifacts" in it. That is, stray pixels that don't match what is around them because the un-compressing didn't guess very well as to what the picture use to look like. 1:19 makes a real mess of even the best photographs. 1:4 is almost unnoticeable in most cases. (The compression and decompression when saving and viewing JPG images is automatic for the most part.)
It would not take long for even the largest memory cards to be filled with images in the 1280x1024 range if they were stored full size, so some compression helps. The physical size of a compressed image will vary depending on the subject matter. A pure white wall will compress well, but a large tree with lots of leaves (and thus detail) will not.
All compression ratios are not always available in all resolutions- read the specification to be sure that these can be selected separately.
Continuous mode (Burst mode): A camera mode that lets you take multiple photos in rapid sequence as you hold the shutter release button down. It is used to capture a series of images or to photograph a fast or unpredictably moving subject.
Continuous tone: An image where brightness appears consistent and uninterrupted; each pixel in a continuous-tone image uses at least one byte for its red, green, and blue values. This allows 256 density levels per color or more than 16 million color mixtures.
Contrast: A measure of the rate of change of brightness in an image; high contrast suggests content consisting of dark blacks and bright whites; medium contrast implies a good spread from black to white; and low contrast implies a small spread of values from black to white.
Converter lens: a lens that attaches to the front of a digital camera, usually requiring an adapter so it mounts correctly on the front of the camera.
Correction of Aberrations at Close Distance Focusing (or CRC): In general, lenses are designed for maximum performance at infinity. Accordingly, when the lens barrel is fully extended to the shortest focusing distance, resolution is reduced. Although this is negligible for ordinary lens, it becomes increasingly important in lens specially designed for close distance photography. lens designers adopted a system where mechanism moves certain lens components as a unit automatically correcting for aberrations. This assures high lens performance throughout the focusing range.
Coated Lens: A lens covered with a very thin layer of transparent material that reduces the amount of light reflected by the surface of the lens. A coated lens is faster (transmits more light) than an uncoated lens.
Color Reversal: Film designed to produce a normal color positive image on the film exposed in the camera for subsequent viewing by transmitted light or projection on to a screen.
color temperature: Description of the color of a light-source by comparing it with the color of light emitted by a (theoretical) perfect radiator at a particular temperature expressed in kelvins (K). Thus "photographic daylight" has a color temperature of about 5500K. Photographic tungsten lights have color temperatures of either 3400K or 3200K depending on their construction.
CMOS: Complementary Metal-Oxide Semiconductor: one of the two main types of image sensors used in digital cameras. Its basic function is the same as that of a CCD. CMOS sensors are currently found in only a handful of digital cameras.
CMYK: Cyan, Magenta, Yellow, Black. The four colors in the ink jets of many photo-quality printers. Some printers use six ink colors to achieve smoother, more photographic prints. The two additional colors are often lighter shades of cyan and magenta.
Compact Flash: A common type of digital camera memory card, about the size of a matchbook. There are two types of cards, Type I and Type II. They vary only in their thickness, with Type I being slightly thinner. A Compact Flash memory card can contain either flash memory or a miniature hard drive. The flash memory type is more prevalent.
Component: Part of a compound lens consisting of one element (single lens) or more than one element cemented or otherwise joined together. A lens may therefore be described as 4-element, 3-component when two of the elements are cemented together.
Composition: The pleasing arrangement of the elements within a scene-the main subject, the foreground and background, and supporting subjects.
Computerized flash: Electronic flash guns which sense the light reflected from the subject, and cut off their output when they have received sufficient light for correct exposure. Most units must be used on or close to the camera for direct lighting only. And the camera lens must be set to a specific aperture (or a small range of apertures) determined by the speed of the film in use.
Condenser: Generally a simple lens used to collect light and concentrate it on a particular area, as in enlarger or projector. Frequently in the form of two planoconvex lenses in a metal housing. A condenser, normally of the fresnel type, is used to ensure even illumination of the viewing screens on SLR cameras.
Condenser Enlarger: An enlarger with a sharp, undiffused light that produces high contrast and high definition in a print. Scratches and blemishes in the negative are emphasized.
Contact Print: A print made by exposing photographic paper while it is held tightly against the negative. Images in the print will be the same size as those in the negative.
Contact Printer: A device used for contact-printing that consists of a lighttight box with an internal light source and a printing frame to position the negative against the photographic paper in front of the light.
Continuous Servo AF Focus: Autofocus term used by Nikon, the AF sensor detection continues as long as shutter release button is lightly pressed and the reflex mirror is in the viewing position. Useful when the camera-to-subject distance is likely to change.
Contrast: The range of difference in the light to dark areas of a negative, print, or slide (also called density); the brightness range of a subject or the scene lighting. It may be also explained as tonal difference. More often used to compare original and reproduction. A negative may be said to be contrasty if it shows fewer, more widely spaced tones than in the original.
Or another way to explain, a difference in visual brilliance between one part of the image and another; without contrast, there would be no such thing as a visible image; a line in a photograph is visible only because it is either darker or lighter in tone than the background; every distinguishable part of the image is the result of a contrast in tonal values.
Contrasty: Higher-than-normal contrast including very bright and dark areas. The range of density in a negative or print is higher than it was in the original scene.
Coma: A lens aberration restricted to off axis image points; the inability of a lens to render point sources of light near the edges of the frame as circular; the points of light appear as comet-shaped blurs (hence the name coma) with the tails flaring toward the center of the image; this aberration is very difficult to eliminate in wideangle lenses with large maximum apertures; improves by stopping down the lens.
Continuous Servo (Nikon's term): AF Focus detection continues as long as shutter release button is lightly pressed and the reflex mirror is in the viewing position. Useful when the camera-to subject distance is likely to change.
CPU (Central Processing Unit): The electronic component that controls an electronic product's functions. Essentially, all automatic cameras have at least a CPU to control various functions of the cameras. Some top models have three to five CPU to handle individual task functions - some handle the exposure, one handle the autofocus and so on. The latest on some top models utilizing 8 or 16 bits chips now. Newer autofocus lenses have built-in CPUs to relay information relating to focal length, distance info, lens type to the camera body for exposure to AF processing.
CRC (Close Range Correction System): Check Nikon's terms page for more.
Crop: The action of trimming away the unwanted parts of an image.
Cropping tool: An applet found within photo-editing software that allows one to trim away unwanted parts of an image.
Curvature of Field: This optical defect causes points on an object plane perpendicular to the lens axis to focus on a curved surface rather than a plane.
Cyan: One of the three primary colors in color prints (coupled with magenta and yellow).
D
Daguerreotype: Photo process developed by Joseph Daguerre that produces an extremely grainy, gray or sepia-toned (brownish) image; presently used to artificially convey age.
Dark voltage: Also called dark current, this is the voltage from a CCD when no light is incident on the CCD.
Decompression: Process of returning a compressed file to its full bitmap.
Dedicated Flash: A fully automatic flash that works only with specific cameras. Dedicated flash units automatically set the proper flash sync speed and lens aperture, and electronic sensors within the camera automatically control exposure by regulating the amount of light from the flash. A simple glance can differentiate by identifying the multiple contacts on the hot shoe (the place where the flash is mounted).
Definition: The clarity of detail in an image; dependent upon resolution (number of pixels) and contrast.
Delayed action: Mechanism delaying the opening of the shutter for some seconds after the release has been operated. Also known as self-timer.
Densitometer: An instrument used for measuring the optical density of an area in a negative or print.
Density: The blackness of an area in a negative or print that determines the amount of light that will pass through it or reflect from it. Sometimes referred to as contrast.
Depth-of-field (DOF): Refers to how much of a photo is in focus when the camera is focused on the main subject. Depth-of-field is controlled by a camera's aperture, in conjunction with the focal length of the lens. Deep (more) depth-of-field means that all or most of the picture is in focus from front to back. Shallow (less) depth-of-field means that a subject is in focus but objects in front and behind it appear out of focus.
Derived image: An image that was created from another image.
Diaphragm: An adjustable device inside the lens which is similar to the iris in the human eye; comprised of six or seven overlapping metal blades; continuously adjustable from "wide open" to "stopped down"; controls the amount of light allowed to pass through the lens and expose the film when a picture is taken; a]so controls the amount of depth of field the photograph will have; in lenses designed for single-lens reflex cameras, there are basically two types of diaphragms: Lens opening. A perforated plate or adjustable opening mounted behind or between the elements of a lens used to control the amount of light that reaches the film. Openings are usually calibrated in f-numbers. The more blades used will have a more natural and rounded spots.
There are two types of diaphragms:
Automatic: The most popular type; controlled by a single aperture ring; during viewing and focusing, the diaphragm remains wide open, allowing the maximum amount of light to go to the viewfinder for a bright and easy-to-focus image; at the instant of exposure, it stops down automatically to a particular aperture and then reopens to full aperture immediately afterward.
Manual Preset: Used in some specific lenses like, PC-Nikkor lens for Nikon for instance; controlled by two separate rings; the preset ring is first set to the desired aperture, then the aperture ring is rotated to stop down the diaphragm manually for metering or prior to taking pictures.
Diffuse Lighting: Lighting that is low or moderate in contrast, such as on an overcast day.
Diffusing: Softening detail in a print with a diffusion disk or other material that scatters light.
Diffusion-Condenser Enlarger: An enlarger that combines diffuse light with a condenser system, producing more contrast and sharper detail than a diffusion enlarger but less contrast and blemish emphasis than a condenser enlarger.
Diffusion dithering: A method of dithering that distributes pixels randomly rather than using a set pattern.
Diffusion Enlarger: An enlarger that scatters light before it strikes the negative, distributing light evenly on the negative. Detail is not as sharp as with a condenser enlarger; negative blemishes are minimised.
Digital: Any system or device that stores information in a format suitable for computers to read; digital information is stored in bits, where each bit is represented as on/off or one/zero.
Digital camera: A camera that captures the photo not on film, but in an electronic imaging sensor that takes the place of film.
Digital image: An image composed of pixels.
Digitization: The process of converting analog information into a digital format for use on a computer.
Digital zoom: A simulated zoom. The physical length of the lens does not change. The camera pre-crops the central portion of an image and reduces its resolution giving an appearance of zooming in. Image quality is degraded and contains increased noise (see optical zoom).
DIN: Deutche Industrie Norm (Film speed rating defined by the Deutscher Normenausschuss (German standards organization).). Numeric rating used to describe emulsion speed for German Made photosensitive materials. Just as the same as ASA and ISO numbers.
Diopter Correction: This is like a focus adjustment that matches the focus of the camera's optical viewfinder to the user's eyesight. This way, users don't have to wear their glasses when using the camera. As some of the viewfinders are quite small and difficult to use with your glasses on, diopter correction can be a welcome option for eyeglass wearers.
Disc: Term used to describe optical storage media (laserdisc, compact disc).
Disk: Term used to describe magnetic storage media (floppy disk, hard disk).
Dispersion: The property of materials which have a refractive index that varies according to the wavelength of light, i.e., bend the rays of some colors more than others; a prism placed in the path of a ray of white light bends the blue and violet rays more than the orange and red, so that it spreads out or "disperses" the colors as a continuous spectrum.
Distortion: Even if the other possible aberrations were totally eliminated, images could result that still have a distorted appearance. For an example, an rectangle may appear as a barrel or pin cushion-shaped object. A lens aberration which does not affect the sharpness of the image, but alters the shape of objects; the inability of a lens to render straight lines perfectly straight; does not improve by stopping down the lens; there are two types of distortion:
Barrel: Straight lines are bowed in at the edges of the picture frame resembling the sides of a barrel; pres ent in small amounts in some wideangle or wideangle-zoom lens, but uncorrected in fisheye lenses.
Pincushion: The opposite of barrel distortion; straight lines are bowed in toward the middle to resemble the sides of a pincushion; present in small amounts in some telephoto and telephoto-zoom lenses.
Dithering: A method of simulating many colors or shades of Grey by combining only a few; for instance, red and blue dots are dithered to make purple. Dithering allows a photo with millions of colors to be displayed on a 256-color monitor and printed on a 4-color printer.
Dodging: Selectively lightening part of a photo with an image editing program.
Also called holding back; in traditional darkroom work, the hand of the developer or a piece of cardboard would be used to block light passing from the enlarger to the print, thus lessening the exposure in only specific parts of the picture. Digitally, the effect is to lighten part of the image without affecting the rest.
Double Exposure: Two pictures taken on one frame of film, or two images printed on one piece of photographic paper. Some cameras can have double exposure level depressed with multiple exposures one even with a motor drive.
Download, downloading: The process of moving computer data from one location to another. Though the term is normally used to describe the transfer, or downloading, of data from the Internet, it is also used to describe the transfer of photos from a camera memory card to the computer. Example: I downloaded photos to my PC.
DPI: Dots per inch: A measurement of the resolution of a digital photo or digital device, including digital cameras and printers. The higher the number, the greater the resolution.
Duotone: An offset-printed image created with two different colors of ink.
Dust: One problem of DSLRs is that when you remove lenses, the sensor area becomes exposed to ambient air, and can collect dust. Moreover, moving parts inside the camera can create fine particles, too, and these can deposit on the sensor. (This wasn’t a real problem with film cameras, because the “sensor” -film- changed with every frame). Most manufacturers now offer dust removal systems with their cameras. Good technique (holding the camera face down when changing a lens, avoiding changing lenses in very dusty environments, for instance) will reduce the risks of gathering dust.
DX: Digital Index. Coding on the film cartridges used to transmit information in relation to film speed, the length of film and the exposure latitude to the camera. Most films - except some technical films are DX coded - means you need not to worry about wrong setting of the ISO setting of film speed anymore, reducing chances of mistakes. Common speed ISO 25 to 6400 - depends on camera models.
DX Data Exchange: Electrical coding system employed in 35 mm format film that communicates film speed, type and exposure length to the camera.
Dynamic range: The gradations and range of light intensities (between total black and total white) that a sensor can detect and record. For instance, past a certain brightness, any sensor will saturate and will not be able to display colors accurately, delivering an over-exposed (pure white) output. This often happens when using a flash to photograph a close subject, or under bright sunlight. Larger sensors, such as those found in DSLRs, typically have a much broader dynamic range.
E
Easel: A device to hold photographic paper flat during exposure, usually equipped with an adjustable metal mask for framing.
ED: Extra Low dispersion - usually refer to glass type. Glass with ED properties indicating special rare earth glass or special formulated glass that limiting or correcting of light rays passing through the lens elements to achieve all spectrum of colors to falls on the same plane of focus - especially the Red and Blue spectrum and is usually more apply to longer focal length lenses where the problem is more serious. First popularized by Nikon's Nikkor lens line - with a gold lining in the front part of the lens. Pentax, Olympus use the same name as Nikon. Canon's version is called "LD" - with red lining and usually their lenses are white in color. While Minolta uses APO. Independent lens makers, like Tamron, uses LD, Sigma uses APO, Tokina's version is SD APO; all these trade names are basically performing the same functions. Also please refer to "apodchromatic" . Check Nikon's terms page for more.
Effective aperture: The diameter of the bundle of light rays striking the first lens element that actually pass through the lens at any given diaphragm setting.
EIS: Electronic Image Stabilizer. Feature that minimizes effect of camera shake. Originally designed for video cameras. Canon has transfer the technology over to its EF lenses, we expect more Canon's EF lenses will adopt this feature.
Electric flash: Refers to the gradations of light and dark that a digital camera can capture where details are neither washed out by light nor concealed by shadows.
Element: Single lens used in association with others to form a compound construction.
Enhanced Back-Printing: An Advanced Photo System feature available in some system cameras that enables users to encode detailed information at the time of picture-taking, such as the date and time of exposure, camera settings, roll title or other custom information for subsequent printing onto the back of their photographs.
Enlargement: A print that is larger than the negative or slide; also see "blowup".
Enlarger: A device consisting of a light source, a negative holder, and a lens, and means of adjusting these to project an enlarged image from a negative onto a sheet of photographic paper.
EPS: Encapsulated Postscript, a computer file standard set by Adobe for printers, which is the mathematical definition of shapes, lines, color and space. This is one of the most accurate ways to define a font or image, but creates much larger file size. EPS files also add page description information to the files. Used on all computer, but not all postscript files are the same, nor readable between programs. EPSF is an IBM file generally, EPSP is usually found on Macintosh, and there are many different variations of each type.
EV: Exposure value. Method of quantifying scene brightness. Most of these value apply to metering cells, how high or low eg. a metering that can handles from EV1-EV21 means a metering system that can measure brightness level from just above the light level of a candle light to a brightly sunlight scene on a beach. Camera metering can handle more weakly on a spot meter than, say, a center weighted average metering system. EV is commonly used in black & White photographic process. At ISO 100, the combination of a one-second shutter speed and an aperture of F1.4 is defined as EV1. The camera may be used only within the EV range of the exposure meter. For example, the exposure metering range s from EV0 to EV20 can be used on a camera, means the camera's meter can handle broader range of exposure latitude.
EXIF: Exchangeable Image File: the file format used by most digital cameras. For example, when a typical camera is set to record a JPEG, it's actually recording an EXIF file that uses JPEG compression to compress the photo data within the file.
EXIF: Exchangeable Image File: Data that is stored in jpeg and TIFF image files, such as shutter speed, date and time, focal length, exposure compensation, metering pattern and if a flash was used a the time a photo was taken. EXIF data can be read by applications which support JPEG including web browsers, image editing programs and some printer software drivers.
Existing Light: Available light. Strictly speaking, existing light covers all natural lighting from moonlight to sunshine. For photographic purposes, existing light is the light that is already on the scene or project and includes room lamps, fluorescent lamps, spotlights, neon signs, candles, daylight through windows, outdoor scenes at twilight or in moonlight, and scenes artificially illuminated after dark.
Export: A software function that allows you to save a copy of information produced in one format into a file of another format.
Exposure: The amount of light that reaches the film; the combination of f-stop and shutter speed, which controls the amount of light that passes through the lens to the film.
Exposure: The exposure setting in a camera is what regulates how much light is used to create the image. It doesn't matter whether it is a film camera or a digital camera. The exposure can be controlled in two ways; aperture adjustment and shutter speed adjustment
When you press the shutter release button of a digital camera, a metering cell measures the light coming through the lens and sets the aperture and shutter speed for the correct exposure. When the shutter opens briefly, each pixel on the image sensor records the brightness of the light that falls on it by accumulating an electrical charge. The more light that hits a pixel, the higher the charge it records. Pixels capturing light from highlights in the scene will have high charges. Those capturing light from shadows will have low charges.
When the shutter closes to end the exposure, the charge from each pixel is measured and converted into a digital number. The series of numbers can then be used to reconstruct the image by setting the color and brightness of matching pixels on the screen or printed page.
Exposure compensation: In photography, exposure compensation allows you to intentionally under- or overexpose a shot to achieve a particular effect.
Exposure compensation: Increase or decrease the exposure an image from the exposure automatically selected by a camera metering system (see bracketing). This can be done for effect or to compensate for some particular lighting situation. This is often referred to as EV compensation.
Exposure factor: A figure by which the exposure indicated for an average subject and/or processing should be multiplied to allow for non-average conditions. Usually applied to filters. Occasionally to lighting. Processing, etc Not normally used with through-the-lens exposure meters.
Exposure Latitude: The range of camera exposures from underexposure to overexposure that will produce acceptable pictures from a specific film.
Exposure/focus lock: the ability to point at one part of the scene and hold the shutter button half-way down to lock in exposure and focus settings then point the camera elsewhere to compose the scene.
Exposure meter: Built-in digital camera meter that measures the amount of light when framing a photo and determines the best exposure. Matrix (Evaluative), Spot and Center-weighted are the main metering types; some digital cameras have all three.
Exposure shift: See exposure compensation.
Exposure values (EV): Exposure Values are numbers that refer to various combinations of lens aperture and shutter speed. When bracketing a photo, decrease the EV if a scene will appear too light (over-exposed). Increase the value if a scene will look too dark (under-exposed).
Extension bellows: Device used to provide the additional separation between lens and film required for close-up photography. Consists of extendable bellows and mounting plates at front and rear to fit the lens and camera body respectively.
Extension tubes: Metal tubes used to obtain the additional separation between lens and film for close-up photography. They are fitted with screw thread or bayonet mounts to suit various lens mounts.
External flash: A supplementary flash unit that connects to the camera with a cable, or is triggered by the light from the camera's internal flash. Many fun and creative effects can be created with external flash.
F
F-number: The numbers on the lens aperture ring and the camera's LCD (where applies) that indicate the relative size of the lens aperture opening. The f-number series is a geometric progression based on changes in the size of the lens aperture, as it is opened and closed. As the scale rises. each number is multiplied by a factor of 1.4. The standard numbers for Calibration are 1.0,1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32, etc., and each change results in a doubling or halving of the amount of light transmitted by the lens to the film plane.Basically, calculated from the focal length of the lens divided by the diameter of the bundle of light rays entering the lens and passing through the aperture in the iris diaphragm.
F-stop: Useful for determining the maximum flash to-subject distance for flash photography.
Fiber-optics: An optical system that uses glass or transparent plastic fibers as light-transmitting media; a fiber-optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.
File: A computer document.
File format: A format for encoding visual information in a file; some common image file formats include TIFF, PICT, and EPS files.
Fill: This is a process that allows you to alter a selected area of an image with a computer graphics program, covering or combining it with a gray shade, a color, or a pattern.
Fill flash: A flash technique used to brighten deep shadow areas, typically outdoors on sunny days. Some digital cameras include a fill flash mode that forces the flash to fire, even in bright light.
Fill-in flash: Forces a flash to go off even in bright light; often used outside to soften dark areas or shadows. The camera will expose for the background first, then add enough fill-flash to illuminate your subject. Fill-in flash is also known as forced flash or flash on.
Film recorder: A device used to record a digital image onto photosensitive film.
Filmstrip: This is a file format developed by Adobe allowing sequential images from a movie to be transferred between Premiere and Photoshop.
Filter: A tinted-glass or plastic lens that fits onto the camera lens to alter the visual field.
Filter: A colored piece of glass or other transparent material used over the lens to emphasize, eliminate, or change the color or density (ND) of the entire scene or certain areas within a scene. Also see "color temperature", "UV". Technically, it explained as a piece of material which restricts the transmission of radiation. Generally colored to absorb light of certain colors. Can be used over light sources or over the camera lens. Camera lens filters are usually glass either dyed or sandwiching a piece of gelatin in a screw-in filter holder.
Fire: Slang for shooting a picture. Example: I pressed the shutter button to fire.
FireWire: A type of cabling technology for transferring data to and from digital devices at high speed. Some professional digital cameras and memory card readers connect to the computer over FireWire. FireWire card readers are typically faster than those that connect via USB. Also known as IEEE 1394, FireWire was invented by Apple Computer but is now commonly used with Windows-based PCs as well.
Firmware: An Often-used microprogram or instruction set stored in ROM. Usually refers to the ROM-based software that controls an unit. Firmware is found in all computer based products from Cameras to Digital Peripherals.
Fish-eye lens: This is an extremely wide-angle lens. A fish-eye lens magnifies the parts of the image near the center of the image and reduces the parts that are far away from the center.
Fisheye lens: Ultra-wide angle lens giving 180 angle of view. Basically produces a circular image on 35 mm, 5-9 mm lens showing whole image, 15-17 mm lens giving a rectangular image fitting just inside the circle, thus representing 180 across the diagonal.
Fixed-focus lens: A lens in which the focus is preset and is not adjustable.
Flare: The reflected light from lens elements that appears as a non-uniform haze or as bright spots on the film. This usually happens when a bright light directly enters the lens.
Flash exposure compensation: Digital camera control that lets you adjust the amount of output from the flash. Increase or decrease the amount to lighten or darken the effect of the flash.
Flash Bracket: Often called handle mount flash. It comprised of one arm of the L-shaped bracket extends under the camera body and uses the camera's tripod socket to mount the camera on the bracket. The vertical arm of the bracket serves as a handle and mounts a flash unit in an accessory shoe often on top of the handle portion, but there are other methods. Flash mounted in a bracket usually requires a separate electrical cord to make the electrical connection between camera body and flash unit.
Flashbulb: Light source based on ignition of combustible metal wire in a gas filled transparent envelope. Popular sizes are usually blue-coated to give light approximating to daylight. Flash bulbs come in various sizes and types. All work by burning metal' foil in an oxygen 'atmosphere within the glass bulb. Because the light is caused by combustion inside the glass envelope, light intensity increases from zero as combustion begins. It reaches a peak value and then falls off as combustion ends. The flash unit is fired or triggered by the shutter mechanism in the camera. For some flashbulb types in some cameras, the shutter mechanism fires the flash and then waits for a specified time delay before it actually opens the shutter. This delay is to allow the flash bulb to get up to full brightness. See more on FP (focal plane bulb) section.
Flash card: A memory card that works with the flash memory, allowing the camera to retain data after the system has been turned off.
Flashcube: Self-contained unit comprising four small flashbulbs with own reflectors. Designed to rotate in special camera socket as film is wound on. Can be used in a special adapter on cameras without the socket. But will not rotate automatically.
Flash memory: A memory chip that has the ability to retain image data even after the host system has been shut off; this feature insures that, even if the digital camera's batteries die, the image data will remain stored in the camera's memory.
FlashPix: The popular trade name for a multi-resolution image-file format developed by Kodak, Hewlett-Packard, Microsoft, and Live Picture.
Flash Range: The effective distance the strobe light can illuminate the subject. Most digital cameras that have built-in strobe lights are effective to about 12 to 15 feet. It varies by brand so check the specifications carefully.
Flash Sync: A special socket on a camera that allows to attachment of an auxiliary strobe light for flash pictures. It is synchronized to the camera's shutter so the light goes off at the right time. Most all 35mm SLRs and a few digital cameras have this feature. Some 35mm SLRs have a "hot shoe" which is a special mount built into the camera that allows for attaching a strobe light.
Flash sync speed: Exposure time with a focal-plane shutter is measured from the instant the first curtain is released, to begin its travel across the frame, until the instant the second curtain is released, to begin its travel across the frame. When the first curtain reaches the end of its travel, the film frame is uncovered as far as the first curtain is concerned, so it closes the electrical contacts for X sync and fires the flash instantly. Shutter speed at which the entire f ilm frame is exposed when the flash s fired in flash shooting. Most modern camera with vertical travel shutter curtain have faster flash sync speed like 1/250 sec. or slower, some top camera model like Nikon F5, changeable to 1/300 sec. with the Custom Setting.
Flash output level compensation: A control used to adjust a TTL auto flash operation, enabling an increase or decrease of flash output to lighten or darken the flash effect.
Flash shooting distance range: The distance range over which a flash can effectively provide light. Flash shooting distance range is controlled by the amount of flash output available. Each automatic Speedlight's flash output varies from maximum duration to minimum duration Close-up subjects will require lower (to minimum) output while more distant subjects will require more light up to the maximum output. The flash shooting distance range varies with the aperture, film speed, etc.
Flat: Too low in contrast. The range in density in a negative or print is too short or in some cases, reflecting the low resolution produced by a low quality lens.
Flat Lighting: Lighting that produces very little contrast or modeling on the subject plus a minimum of shadows.
Flatbed scanner: This is an optical scanner in which the original image remains stationary while sensors scan the material from beneath the image.
FL: Florite. A low dispersion mineral used as a substitute for glass in some highly corrected long focal length lens. Canon uses most of these properties on its EF-L series long telephoto. Also refer to "ED"
Focal length: The distance from the surface of the lens to the focal point or center point at which light rays converge; the focal length determines the length of the lens.
Focal Length: A lens' angle of view, most commonly indicated as wide-angle, normal or telephoto. Usually compared to a 35mm camera's lens.
The lens in a digital camera is almost always smaller than in a 35mm SLR (single lens reflex) camera. Because of that the actual focal lengths mean little to those who are already familiar to photography. To assist in understanding, digital camera manufacturers state the focal lengths of the lenses in terms of "35mm equivalent."
The focal length is measured in millimeters, the lens on a digital camera is marked with its focal length and this is typically a very small number such as 6 - 15mm, in traditional 35mm photography everyone is "used to" the common focal lengths of 28mm, 50mm, 200mm etc. Because the CCD in a digital camera is much smaller than a 35mm negative the lenses can be made smaller (because of this they have to be of a much higher quality), to get the true focal length you need to multiply this small size by a value called the "focal length multiplier" (this is especially important for digital SLR's which take normal 35mm lenses).
lenses, with a range of focal lengths running from a mild wide-angle (roughly equivalent to a 35mm lens on a 35mm camera) out to a mild telephoto (slightly more than the equivalent of a 100mm lens on a 35mm camera). While you invariably pay more for a camera with zoom capability, we've found the feature very useful in real-life shooting situations.
Focal length multiplier: Most sensors used in DSLRs have a smaller area than the surface of 35mm film. Yet, for historical and convenience reasons, focal lengths are still expressed in the 35mm format. This means that each camera’s effective focal length will be different than the one listed on a lens. To calculate the effective focal length of a lens and camera combination, the user must use the focal length multiplier of the camera. Canon’s entry-level cameras’ multiplier is usually 1,6, though their higher-end models do not have a multiplier. Nikon, Sony and Pentax usually have a multiplier of 1,5, while four-thirds systems (such as Olympus and Panasonic) have a multiplier of 2. As an example, a 50 mm lens on a Nikon camera would have an effective focal length of 75 mm, while a 12-48 mm zoom lens on a four-thirds system would have an effective reach of 24-84 mm.
Focal Length: The distance between the film and the optical center of the lens when the lens is focused on infinity. The focal length of the lens on most adjustable cameras is marked in millimetres on the lens mount. The distance from the principal point to the focal point. In 35mm-format cameras, lenses with a focal length of approx. 50mm are called normal or standard lenses. lenses with a focal length less than approx. 35mm are called wide angle lenses, and lenses with a focal length more than approx. 85mm are called telephoto lenses. lenses which allow the user to continuously vary the focal length without changing focus are called zoom lenses .
FP (Focal Plane) flash Bulb: A special flashbulb that can be used at certain shutter speeds is called "FP" where the initials stand for Focal Plane. Designed for use with focal-plane shutters these bulbs make a nearly uniform amount of light for a relatively long time. Generally, FP flashbulbs can be used with any shutter speed and any firing delay except "X sync". The FP bulb will extinguish during exposure intervals longer than 1/60 second but enough light will have reached the film to make the exposure.
Focal-Plane Shutter: An opaque curtain containing a slit that moves directly across in front of the film in a camera and allows image-forming light to strike the film.
Focal range: This refers to the entire area that is in focus.
focus To move the lens or film/image sensor in order to record a sharp image.
Focus: Camera lenses have to be focused on the subject to create a clear image just like your eyes do. Some cameras feature a lens with "fixed focus." This means that the lens was designed to be in focus all the time. This range is usually from about ten feet to infinity. Fixed focus lenses are usually found in cameras in the lower price ranges.
Better cameras have auto focus. There is some sort of mechanism in the camera that moves the lens elements to bring the image into focus. Some cameras are quite good at this and some have difficulty in low light situations. Most digital cameras have some sort of setting to force the camera to focus into some range such as Macro and Distant.
A small number of digital cameras also feature manual focus. If the camera has a decent auto focus feature then manual focus is not necessary.
Frame grabber: A photo-editing program tool used to move menus and palettes around on the screen.
Focus Range: The range within which a camera is able to focus on the selected picture subject - 4 feet to infinity - for example.
Focus-Priority for autofocus: Shutter cannot be released until the subject s in focus. For situations when an in-focus subject s important. With the F5 camera body, Focus-Priority s given to Single Servo AF mode while Release-Priority is given to Continuous Servo AF. Using Custom Setti ing, however, you can change the priority to Release-Priority Single Servo AF or Focus-Priority Continuous Servo AF.
Focus Tracking: Enables the camera to analyze the speed of the moving subject according to the focus data detected, and to obtain correct focus by anticipating the subject's position and driving the lens to that position at the exact moment of exposure, basically a Nikon's and Canon's feature. Currently, Nikon lead the pack in this technology with the F5, the fastest among all.
Fogging: Darkening or discoloring of a negative or print or lightening or discoloring of a slide caused by exposure to non image-forming light to which the photographic material is sensitive, too much handling in air during development, over-development, outdated film or paper, or storage of film or paper in a hot, humid place.
Format: The actual size of the photograph, either slide or negative, produced by a camera; in 35mm photography, the picture measures 24mm x 36mm and has a diagonal of 43mm, While the new APS (Advance Photo System), several new formats were included, including panorama . While it can also be explained as shape and size of image provided by camera or presented in final print or transparency. Governed in the camera by the opening at the rear of the body over which the film passes or is placed. The standard 35 mm format is 36 x 24 mm; half-frame, 18 x 24 mm; 126 size, 28 x 28 mm; 110, 17 x 13 mm; standard roll film (120 size), 2x 2 in.
Four-thirds: A lens system and sensor size mainly supported by Olympus and Panasonic. The four-thirds system aims at standardizing the lens mounts, sensor size and communication protocol between camera and lens. The idea is to make the lenses and camera bodies interchangeable between brands. The four-thirds system is a digital-only system, meaning that no film camera is standardized for it. The sensors used in the four-thirds system are slightly smaller than most other digital sensors, allowing lenses to also be physically slightly smaller. The smaller sensors also mean that noise levels are often a bit higher than what is obtained with larger sensors.
Foreground: The area between the camera and the principal subject.
Front-Curtain Sync: The flash fires an instant after the front curtain of a focal plane shutter has completed its travel across the film plane. This is the way the camera operates with the flash sync mode at Normal Sync. (See "Rear-Curtain Sync".)
Fresnel: Pattern of a special form of condenser lens consisting of a series of concentric stepped rings, each ring a section of a convex surface which would, if continued, form a much thicker lens. Used on focusing screens to distribute image brightness evenly over the screen.
Fps: Frames per second. Used to describe how many frames can the motor drive or winder can handle automatically on winding per second consequently. Also apply to areas like video, animations, movie cameras.
Free working distance: In close-up photography, the distance between the front of the lens and the subject; increases as the focal length increases; important consideration when photographing shy or dangerous subjects or when using supplementary illumination.
Frontlighting: Light shining on the side of the subject facing the camera.
FRPS: Fellow of the Royal Photographic Society of Great Britain. Most salon photographers dream to have a title on their belt. A reconition that a photographers' standard in photographic field.
Frame: One individual picture on a roll of film. Also can apply to a object that can be utilised (tree branch, arch, etc.) to frame a subject in composition.
Frontlighting: Light shining on the side of the subject facing the camera.
FPX: Short for flashpix; an emerging World Wide Web standard file format for images.
F-stop: A means of measuring the width of the diaphragm opening, which determines how much light passes through the lens. Smaller numbers in an f-stop correspond to wider lens openings; as the f-stop reading increases in number, the lens opening decreases inversely.
Full frame: A sensor format that corresponds to the area of traditional 35 mm film, mainly used by Canon in some high-end models. Full-frame cameras have no focal length multiplier (or, said differently, they have a multiplier of one). lenses designed specifically for digital cannot be used on full-frame cameras, except if the user is willing to accept strong vignetting in all circumstances.
Full-screen image: A digital image that takes up the entire computer screen.
Full aperture metering: TTL metering systems in which the camera simulates the effect of stopping down the lens when the aperture ring is turned, while leaving the diaphragm at full aperture to give full focusing screen brilliance. The meter must be "programmed" with the actual full aperture, and the diaphragm ring setting.
G
Gamma correction: A digital image that takes up the entire computer screen.
Gamut: The range of colors that can be captured or represented by a camera or graphics device.
Ghost images: Bright spots of light, often taking the shape of the aperture, which appear in the camera viewfinder or in the final photograph when a lens is pointed at a bright light like the sun; controllable through the use of multilayer coating of the lens elements.
GIF: Graphic Interface designed by CompuServe for using images on line. This is a 256 color or 8 bit image.
GIF 89: The most recent GIF standard that allow the selection of area for transparency, primary use is on the internet and other on-line services. Like GIF it is 256 color or 8 bit imaging
GN (Guide number): flash-to-subject distance = guide number divided by f-stop
f-stop = guide number dived by flash subject distance
Used to express the power output of the flash nit. It indicates the power of a flash in relation to ISO film speed. Guide numbers are quoted in either meters or feet. Guide numbers are used to calculate the f/stop for correct exposure as follows: Number calculated by multiplying proper flash exposure aperture by the subject distance.
GPD: Gallium Photo Diode. Metering cells for measuring exposure, using gallium arsenide-phosphide, just like SPD or Cds cells.
Gradient fill: An image fill that gradually transitions from one color to another; commonly used in graphics editors.
Grain: Minute metallic silver deposit, forming in quantity the photographic image. The individual grain is never visible, even in an enlargement, but the random nature of their distribution in the emulsion causes over-lapping, or clumping, which can lead to graininess in the final image. Also cross check with below for graininess.
Graininess: The sand-like or granular appearance of a negative, print, or slide. Graininess becomes more pronounced with faster film and the degree of enlargement.
Granularity: An image fill that gradually transitions from one color to another; commonly used in graphics editors.
Grayscale – A photo made up of varying tones of black and white. Grayscale is synonymous with black and white.
Grey card (18% Grey Card): Tone used as representative of mid-tone of average subject. The standard Grey card reflects 18 per cent of the light falling on it.
GUI: Pronounced Gooey , stands for graphic user interface. Refers to the computer interface with software in a user friendly appearance.
H
Halation: The production of "halos" round bright spots in an image, by light reflecting from the back of the film-base. General film bases are given a light absorbing coat the anti-halation back to prevent this.
Hi 8: Video recording format, also refer a High Band 8mm format.
"H"-Format: One of the three selectable Advanced Photo System print formats; identical to the 9:16 aspect ratio used in high-definition television (HDTV); suitable for wider shots than usual, such as groups; produces prints of 3.5 x 6 inches or 4 x 7 inches
Halftone: An image that is reproduced through a series of dots to simulate shades of gray in a photograph; halftone has traditionally been used in the reproduction of images for newspapers and magazines.
High Contrast: A wide range of density in a print or negative.
Highlights: Small, very bright part of image or object. Highlights should generally be pure white, although the term is sometimes used to describe the lightest tones of a picture, which, in that case, may need to contain some detail.
Histogram: A graphic representation of the range of tones from dark to light in a photo. Some digital cameras include a histogram feature that enables a precise check on the exposure of the photo.
Hot shoe: A clip on the top of the camera that attaches a flash unit and provides an electrical link to synchronize the flash with the camera shutter.
Hot Shoe: Usually rest around the pentaprism of the camera (but some were designed around the film rewind knob). It has an electrical contact which mated with a contact in the mounting foot of the flash unit. This allows the camera to fire the flash at the proper time without any other electrical connections between flash and camera.The fitting on a camera that holds a small portable flash. It has an electrical contact that aligns with the contact on the flash unit's "foot" and fires the flash when you press the shutter release. This direct flash-to-camera contact eliminates the need for a PC cord. Some referred it as accessory shoe. Modern flash demand more than just the main electrical contact and often has more dedicated functions such as TTL control, viewfinder ready light etc.and thus, you will find more secondary contacts other than the main.
Hue: The tint of a color as measured by the wavelength of light. Hue is also represented by a position on the color wheel.
Hyperfocal Distance: Distance of the nearest object in a scene that is acceptably sharp when the lens is focused on infinity.
I
Image: Electronic representation of a document, stored and displayed as a bitmap. Various compression techniques are in use to minimize file size and network load.
Imaging: Term commonly used to describe both the products and industry dealing with images.
Image browser: An application that enables you to view digital photos. Some browsers also allow you to rename files, convert photos from one file format to another, add text descriptions, and more.
Image capture: The use of a device, such as a scanner or digital camera, to create a digital representation of an image. This digital representation can then be stored and manipulated on a computer.
Image editor: A computer program that enables you to adjust a photo to improve its appearance. With image editing software, you can darken or lighten a photo, rotate it, adjust its contrast, crop out extraneous detail, remove red-eye and more.
Image processing: The manipulation of images that have been scanned or captured by a digital recording device.
Image resolution: The number of pixels in a digital photo is commonly referred to as its image resolution.
Image stabilization: Image stabilization, IS in short, helps to steady the image projected into the camera to compensate for hand shake. It differs from digital image stabilization found in most digital video cameras as the later involves manipulation of image pixels to create a stable video image.
Incident light: Light falling on a surface as opposed to the light reflected by it.
Index color: This process minimizes the number of colors and file size of a graphic image to 8-bit or less for Web publishing.
Infinity: Infinite distance. In practice, a distance so great that any object at that distance will be reproduced sharply if the lens is set at its infinity position, i.e. one focal length from the film.
Inkjet – A printer that places ink on the paper by spraying droplets through tiny nozzles.
Interpolation: An averaging process used to estimate an unknown image value bracketed by two or more known image values. In image processing, interpolation is used to smooth the edge lines of images when the resolution of the image is changed. Interpolation often tends to overcompensate for lost detail, and the result is a less-than-sharp image.
Interspersed Aspect Ratio: A basic requirement of certified photofinishers and certified photofinishing equipment; specifies the three system print formats - C, H and P - that users select during picture-taking must be available at photofinishing.
Interchangeable lens: Lens designed to be readily attached to and detached from a camera.
Inverted telephoto lens: Lens constructed so that the back focus (distance from rear of lens to film) is greater than the focal length of the lens. This construction allows room for mirror movement when short focus lenses are fitted to SLR cameras.
Iris: Strictly, iris diaphragm. Device consisting of thin overlapping metal leaves pivoting outwards to form a circular opening of variable size to control light transmission through a lens.
IR: Short for infrared.
ISO (Sensitivity): The number indicating the camera sensors sensitivity to light. The higher the sensitivity, the less light is needed to make an exposure (see noise).
ISO speed: A rating of a film's sensitivity to light. Though digital cameras don't use film, they have adopted the same rating system for describing the sensitivity of the camera's imaging sensor. Digital cameras often include a control for adjusting the ISO speed; some will adjust it automatically depending on the lighting conditions, adjusting it upwards as the available light dims. Generally, as ISO speed climbs, image quality drops.
IX Information Exchange: The ability of Advanced Photo System film to communicate with devices, and devices to communicate with film; can be accomplished optically or magnetically using a thin magnetic layer on the film that records digital data.
J
Jaggies: Slang term for the stair-stepped appearance of a curved or angled line in digital imaging. The smaller the pixels, and the greater their number the less apparent the "jaggies". Also known as pixelization.
JCII: Japan Camera Inspection and Testing Institute. Organisation in Japan to monitor export quality of Japanese made cameras, in 1992, may be because of the global localisation programs, most lower end and some mid-range cameras are made and produced in countries outside Japan and their duty is relieved.
JPEG: A standard for compressing image data developed by the Joint Photographic Experts Group, hence the name JPEG. Strictly speaking, JPEG is not a file format, it's a compression method that is used within a file format, such as the EXIF-JPEG format common to digital cameras. It is referred to as a lossy format, which means some quality is lost in achieving JPEG's high compression rates. Usually, if a high-quality, low-compression JPEG setting is chosen on a digital camera, the loss of quality is not detectable to the eye.
K
Kelvin: A scale use to measure the color temperature. 5000 K refer to normal daylight.
Kilobyte: 1024 bytes, written KB. used to refer to size of files, relates to amount of information in a file.
Kit lens: A lens (or lenses) offered as a starter kit with a DSLR camera. Buyers can purchase only the camera body, but kit lenses are an inexpensive starting point for a new DSLR owner. These lenses are rarely excellent, even though they will satisfy many users.
L
Lab Color: L*a*b* is a color model developed by the Centre Internationale d´Eclairage (CIE). These standards are internationally accepted standards for all colormetric measurements. The Lab model, like other CIE color models, defines color values mathematically, in a device independent manner. Lab color is consistent color regardless of the device producing the color.
Latent Image: The invisible image left by the action of light on photographic film or paper. The light changes the photosensitive salts to varying degrees depending on the amount of light striking them. When processed, this latent image will become a visible image either in reversed tones (as in a negative) or in positive tones (as in a color slide).
LCD: Liquid Crystal Display: a low-power monitor often used on the top and/or rear of a digital camera to display settings or the photo itself.
LD: Low dispersion glass, or UD (ultra low dispersion) or SD (Super Low dispersion), please refer to "ED", basically, refers to optically superior glass - price too! Dispersion sometimes also refer as "color fringing".
Leaf shutter: Located in the lens, this camera shutter utilizes a spring with the aperture control device to control the exposure time. It can be synchronised with a flash at any speed.
LED: Short for light emitting diode; an electronic device that lights up when electricity passes through it. LEDs are usually red, and are used for camera viewfinder displays, since they can be seen in the dark.
Lens: An optical device that focuses light rays. In cameras, the lens is the device on the front face (or in a tube extending from the front face) that gathers the incoming light and concentrates it so that it can be directed toward the film (in an optical camera) or the imaging device (in a digital camera).
Lens aberration: Optical flaws which are present in small amounts in all photographic lenses; made up of chromatic aberration, spherical aberration, curvature of field, distortion, etc.; a perfect lens would show the image of a point as a point and a straight line as a straight line, but in practice, lenses are never perfect: they reproduce a point as a patch and a straight line as a more or less curved band; most of the trouble is caused by aberrations, inherent in the lens construction; it's the job of the lens designer to control most of the aberrations as much as possible by combining a number of single lenses in such a way that the aberrations of one lens tend to be canceled out by opposing aberrations in the others.
Lens Shade: A collar or hood at the front of a lens that keeps unwanted light from striking the lens and causing image flare. May be attached or detachable, and should be sized to the particular lens to avoid vignetting.
Lens-Shutter Camera: A camera with the shutter built into the lens; the viewfinder and picture-taking lens are separate.
Lens Speed: The largest lens opening (smallest f-number) at which a lens can be set. A fast lens transmits more light and has a larger opening than a slow lens. Determined by the maximum aperture of the lens in relation to its focal length; the "speed" of a lens is relative: a 400 mm lens with a maximum aperture of f/3.5 is considered extremely fast, while a 28mm f/3.5 lens is thought to be relatively slow.
Light box: A device for viewing developed film or slides. It consists of a box of backlit balanced light behind a glass or plastic surface on which the film or slides are placed for viewing.
Light meter: A light-sensitive measuring device used to evaluate the amount of light focused on a subject in order to set the proper exposure.
Lighting ratio: The ratio of the brightness of light falling on the subject from the main (key) light and other (fill) lights. A ratio of about 3:1 is normal for color photography, greater ratios may be used for effect in black-and-white work.
Limiting aperture: The actual size of the aperture formed by the iris diaphragm at any setting. Determines, but usually differs from, the eflfective aperture.
Liquid Crystal Display (LCD): Monitor on back of a digital camera that shows 100% of the view through the camera lens. Like a viewfinder, it can be used to preview a scene before taking a photo. The LCD also displays camera settings and can be used to review photos and videos saved to a memory card.
Long-focus: Lens of relatively long focal length designed to provide a narrower angle of view than the normal or standard lens, which generally has an angle of view, expressed on the diagonal of the film format, of about 45 degrees The long focus lens thus takes in less of the view in front of it but on an enlarged scale.
Lossless compression: This compression format minimises the size of files by creating an internal shorthand, which restores the image to its original state before compression.
Lossy compression: This compression method minimises file size by eliminating unnecessary data, which causes a slight degradation of image quality.
Low-key image: A dark underexposed image with few light tones.
LPI: Short for lines per inch; refers to the frequency of horizontal and vertical lines on a halftone screen.
Luminence: Refers to the black-and-white information, including brightness, sharpness, and contrast, encoded in a video signal or graphic image.
Lux: A measurement of the light intensity. One Lux in video means light level of a candle light.
M
Macro: Macro focus is the ability of the camera to focus on objects close to the camera- closer than about 12". When used in conjunction with a zoom lens, macro can allow the photographer to fill the viewfinder with small objects- with some cameras, a dime can nearly fill the frame. This is useful with flowers, insects, and other such small items. Some cameras have a different macro distance for the wide angle setting and the telephoto setting.
Magnification ratio: Ratio that express greatest possible on film magnifying power of the lens. Used commonly on the macro setting of the zoom lenses, macro lens or with bellows.
Manual: User selects both shutter speed and aperture, following or ignoring the meter's recommendations to achieve the desired exposure.
Manual flash: Flash output is controlled manually in manual flash mode unlike in auto flash mode, where flash output power varies automatically according to the selected aperture. Some Speedlights, example like the Nikon SB 27, SB 26, SB-25. SB-24 and SB 20, provide selectable manual outputs (full, 1/2, l/4, 1/8, l/16 etc.), while others provide full manual output only.
Manual iris: Diaphragm controlled directly by a calibrated ring on the lens barrel.
Map: The process of making one image conform to the size, shape, and/or texture of another.
Mask: A defined area used to limit the effect of the image-editing operations to certain regions of an image; masks can be drawn manually with a stylus or a mouse, or they can be created automatically.
Matrix Metering: When a digital camera has to set the exposure automatically (the aperture and shutter speed) it often uses matrix metering. The matrix is a set of areas, or spots, in the picture that the camera looks at and averages to decide on aperture and shutter speed settings- the exposure settings. Sometimes this is "center weighted" meaning the most of the spots are in the center of the frame, and sometimes it is bottom weighted.
Mammum aperture: The widest aperture which the diaphragm is capable of opening up to; it is engraved on the lens in this manner; 1: 1.4.
Media: Material that information is written to and stored on. Digital photography storage media includes CompactFlash cards and CDs.
Megabyte (MB): A measurement of data storage equal to 1024 kilobytes (KB).
Megapixel: A measurement of 1,048,576 pixels (approximately 1 million pixels)(picture elements). Digital images are made up of thousands of these tiny, tile-like picture elements.
Memory Cards: These are small memory modules that can be inserted into the camera to hold images. When the card is full it can be removed and another card inserted. The memory on these cards is non-volatile-m that is, they don't lose their images when they are removed form the camera. The images can be later downloaded from the card, and when the images are erased from the card it is ready to be reused. These cards are good for a lot of reuses- one manufacturer just warranted their cards for a minimum of 1,000,000 images.
Memory Stick: A memory card slightly smaller than a single stick of chewing gum. Like CompactFlash and SmartMedia, it is flash-based storage for your photos.
Metering system: Measures the amount of light when framing a photo and determines the best exposure. The main digital camera metering types are: Matrix (Evaluative), Spot and Center-weighted.
Mirror lens (Reflex Lens): Lens in which some (usually two) of the elements are curved mirrors. This construction produces comparatively lightweight short fat long focus lenses. They cannot be fitted with a normal diaphragm.
Moire pattern: An unwanted effect that appears in digital scans of images.
Monochrome: A term used to refer to a bi-level graphic; also refers to a single-channel grayscale image.
Morphing: A special visual effect, used in both film and video, which produces a smooth transformation from one object to another.
Motor Drive: A mechanism for advancing the film to the next frame and recocking the shutter, activated by an electric motor usually powered by batteries. Popular for action-sequence photography and for recording images by remote control.
MTF: Modulation Transfer Function. The way people (who else, the magazines!) uses to measure a lens's ability to hold diminishing details of a subject. Why MTF ? Because, everything is done electronically and eliminating any errors in human judgment or vision and results can be repeatable to counter check earlier tests. Secondly, a precise comprehensive rating is made possible by incorporating huge amount of data into a single reading, lastly it is very fast and permit its use on just out from production lenses.
Multi Capture: Allows a number of pictures to be captured in fast succession. It is the electronic counterpart to motor drives and power winders in film cameras. It allows the camera to take a series of pictures, one right after another, by holding down the shutter release. It can take pictures as fast as from two to four frames per second. As many as from eight to twenty pictures can be captured at one time. The speed and number of frames varies depending on the specific brand and model of camera. This is almost always accomplished in lower resolution modes with the flash off to limit the amount of memory needed and increase the speed of the capture.
Multilayer coating: The depositing of multiple coats of anti-reflective materials on a lens surface to reduce ghost images and flare produced by internal reflections and insure faithful color rendition; in the Nikon Integrated Coating system, the number of layers is determined by the type of optical glass and the position of the element in the lens design.
N
ND filter: Short for neutral density filter; used to reduce the amount of light passing through a lens without altering the image's color or tonal rendition.
Negative: This is a piece of processed film in which the image is reversed so that the shadows are light and the highlights are dark.
Neutral color: In RGB color mode, equal amounts of red, green, and blue make a neutral color.
Nicd or NICAD: Nikel Cadmium. Used as the backbone of most rechargeable batteries. Though not so lasting as alkaline, but have a better resistance to cold than alkaline. When the batteries power is drained out, it will turn "flat" right away (advisable to have spare batteries). Most high speed motor drive handles best when using Nicd batteries.
NiMH – Nickel Metal-Hydride: a type of rechargeable battery that can be recharged many times. NiMH batteries provide sufficient power to run digital cameras and flashes.
Noise: Randomly-spaced speckles (pixels) that can appear in digital images shot at high ISO numbers. Noise results in a reduction of photo detail and clarity, though it can be reduced with special noise reduction software. Noise is most visible when photos are shot at ISO 200 and above with a consumer digital camera. Some digital cameras have a Super CCD where photos taken at higher ISO numbers (eg. ISO 1600) have little, if any, visible noise.
Nonrecoverable error: This is an uncorrectable change in color from that of the original image.
Normal lens: A lens that accommodates an image of approximately the same angle of view and the same proportion as that of which the human eye is capable.
NTSC: National Television Standards Committee. Standards for video broadcasting and recording in the US and Japan. PAL's the standard in Great Britain and the commonwealth countries. SECAM used in many countries in the European communities.
O
Off-The-Film Metering: A meter which determines exposure by reading light reflected from the film during picture-taking or a way of metering meters light reflects off film plane during exposure. First pioneered by Olympus on its famous OM2n, which is real time metering for normal exposure and flash exposures. Most flash mode for modern cameras are with OTF flash mode now.
Online photo printer: A company that receives digital photos uploaded to its Web site, prints them, then sends the prints back by mail or courier.
Opacity: The amount of transparency when combining a fill color, painted color, floating selection, pattern, or layer with another layer or background.
Optical filtering: Refers to the process of selectively transmitting or blocking a range of wavelengths of light.
Optical sampling rate: The number of samples that are captured by a scanner per linear distance as determined by the optics, electronics, and mechanics of the system.
Optical zoom: A true zoom. The focal length of the lens extends and retracts so an image is magnified by the lens itself. Whatever the focal length of the lens, image resolution stays the same. Optical zooms produce the best photo quality (see digital zoom).
OTF Test (Optical Transfer Functions): Evaluates lens performance in terms of resolving power, contrast rendition and abberrations. Most believes the test is the only way to determine how good a lens is in the lab - at least the tester (esp photo magazines) does.
Ortho (Orthochromatic): Denotes film sensitive to blue and green light.
Overexposure: Improper exposure causing an image to look too light. There is a loss of detail in bright areas.
Over Exposed: An over exposed picture means that too much light was allowed to strike the film (or the proper amount of light was allowed to strike the film for too long), That means that the aperture was too large for the exposure time, or the exposure time was too long for the aperture setting. This will give an image that is too bright or washed out.
Overlay proof: A proof created from color separation negatives that uses sheets of acetate overlaid on each other to create the color image. Each film layer represents one color.
P
PAL: Phase Alternation Line. System for minimizing hue errors in color transmission used in the EU.
Palette: A computer graphics term describing the collection of colors or shades available to a graphics system or program.
Pan: A camera technique in which the point of view is adjusted by moving the camera direction along the horizontal plane.
Pan Format: "Pan" format - one of the three selectable Advanced Photo System print formats; a 1:3 aspect ratio that produces prints of 3.5 x 10.5 inches or up to 4.5 x 11.5 inches; suitable for panoramic shots and tall or wide subjects.
Panning: A photography technique in which the camera follows a moving subject. Done correctly, the subject is sharp and clear, while the background is blurred, giving a sense of motion to the photo.
Panorama: A broad view, usually scenic.
Parallax: With a lens-shutter camera, parallax is the difference between what the viewfinder sees and what the camera records, especially at close distances. This is caused by the separation between the viewfinder and the picture-taking lens. There is no parallax with single-lens-reflex cameras because when you look through the viewfinder, you are viewing the subject through the picture-taking lens.
Pattern recognition: Computer-based recognition of forms or shapes within an image.
PC Cords: The purpose of sync cords is to allow the camera to control the flash, so the flash fires at the correct time. Other common names for electrical cords to connect flash to camera are PC cord, sync cord and synch cord. One type of electrical connector on camera bodies is called a PC socket, whence the name, PC cord. Sync and synch are both intended to be abbreviations of the word synchronization.
PC Terminal/PC socket: Some older flash units may not have a hot shoe onthe flash unit and would need cable connection to fire timely. It is a threaded collar surrounding the center electrical part of the socket. Some flash cords have a connector that makes electrical contact with the center part of the socket and is held securely in place by a threaded ring which screws into the outer part of the socket on the camera body. It is another alternative way to sync the electronic flash on the camera. Some of the modern autofocus cameras have omiited this feature on the body. It can also be used to activate another flash unit via sync cord in a multiple flash setup. PC sockets and common PC cords fit together by pushing the connector on the cord into the socket on the camera. It remains connected only because of friction.
PC (photographic 1) : Prontor/Compur. The clip on socket of the flash mode terminal.
PC (photographic 2) : Perspective control. Also known as tilt or shift lenses. lenses that allow for correction of linear distortion resulting from high or low camera angle. Most are with gear or sliding mechanism and most require manual metering.
PCX: Windows Paintbrush bitmap image standard.
PXC: A PC file format used for graphics.
Perspective: The rendition of apparent space in a flat photograph, i.e., how far the foreground and background appear to be separated from each other; determined by only one factor: the camera-to-subject distance; if objects appear in their normal size relations, the perspective is considered "normal"; if the foreground objects are much larger than the ones in the background, the perspective is considered "exaggerated"; when there is little difference in size between foreground and background, we say the perspective looks "compressed."
Phosphors: Tiny red, green, and blue grains on the inside surface of a CRT monitor that are illuminated when an electron beam is directed toward them.
PhotoCD: A popular storage method for digital images developed by Kodak.
Photo File Index Print: A basic system feature that makes ordering reprints and enlargements easy; the small print shows a positive, "thumbnail"-sized version of every picture on an Advanced Photo System film roll; accompanies all prints and negatives returned in the sealed film cassette by the photofinisher; each thumbnail picture is numbered on the index print to match negative frames inside the cassette.
Photolamp (3400K): Photographic lamp giving more light than a normal lamp of the same wattage, at the expense of filament life. Often referred to by the trade mark Photo Hood. Are used with type A color films.
Photometer: Also called a light meter, this is an instrument used to measure luminous intensity, luminous flux, illumination, or intensity of light.
PICT: A Macintosh file format used for graphics.
PictBridge: a standardized technology that lets you print images from a memory card in a digital camera directly to a printer regardless of brand. No computer is necessary.
Picture angle: The angle of coverage of a lens usually measured across the diagonal of the picture frame; varies with focal length: the longer the focal length, the narrower the picture angle; the shorter the focal length, the wider the picture angle. Telephoto ratio Is derived by dividing the distance from the front vertex of a lens to the front vertex by the focal length. The smaller the telephoto ratio, the smaller the total length of the lens.
Pincushion Distortion: The opposite of barrel distortion; straight lines are bowed in toward the middle to resemble the sides of a pincushion; present in small amounts in some telephoto and telephoto-zoom lenses.
Photofinisher Service Certification: Program developed by the System Developing Companies to give special recognition to photofinishers and retailers who provide the minimum Advanced Photo System feature set; an identifying logo signals to consumers which photofinishers and retailers provide all of the mandatory benefits of the system.
Photomicrography: The process of taking photographs of minute objects using a camera and a microscope; not to be confused with "microphotography," the process of making minute photographs of large objects.
Pixel: Picture Element: digital photographs are comprised of thousands or millions of them; they are the building blocks of a digital photo.
Pixel dropping: A subsampling technique used to reduce the number of pixels in an image by dropping every nth pixel from the scan.
Pixelisation: The graininess in an image that results when the pixels are too big, relative to the size of the image.
Plane: Level surface. Used in photography chiefly in respect to focal plane, an imaginary level surface perpendicular to the lens axis in which the lens is intended to form an image. When the camera is loaded the focal plane is occupied by the film surface.
Plug-In: The plug-in architecture was first popularized by Adobe Photoshop and is now the defacto standard for all major imaging programs. Unlike Twain it allows more flexibility in design so acquire, export, and specific task can be performed with in a software application. This is the preferred choice of operation in the Macintosh and ´Power User´ computers. Plug-In ideology has spread to other applications like Netscape Navigator, Macromedia Director, and so on. Not all plug-ins work with all products, specific interfaces are required for different types of software. Adobe has become the defacto standard for image editing software, and graphic illustration software.
PMS: Short for Pantone Matching System; a trademarked standard for specifying and producing spot colors using proprietary ink mixes.
Polarization: This is the use of specific filters to control the direction light travels. Effects include the reduction of glare and reflections and the saturation of colors, especially in landscapes.
Polarising filter: These are two pieces of polarising material that rotate on a common axis so that the polarising effect can be increased or decreased on the camera lens.
Polarized light: Light waves vibrating in one plane only as opposed to the multi-directional vibrations of normal rays. Natural effect produced by some reflecting surfaces, such as glass, water, polished wood, etc., but can also be simulated by placing a special screen in front of the light source. The transmission of polarized light is restrained by using a screen at an angle to the plane of polarization.
Positive: Also referred to as a slide or transparency; this is a photographic image in which the light areas correspond to light areas in the subject, and the dark areas correspond to the shadow areas in the subject.
Posterisation: The effect produced when a photographic image is displayed or printed with a small number of colors or shades of grey.
PPI: Pixels per inch; the measurement of resolution for display or print elements.
Preset iris: Diaphragm with two setting rings or one ring that can be moved to two positions. One is click-stopped, but does not affect the iris, the other moves freely and alters the aperture. The required aperture is preset on the first ring, and the iris closed down with the second just before exposure.
Primary colors: Three colors (red, yellow, and blue), which when combined at various proportions can produce every other color.
Print: A positive picture, usually on paper, and usually produced from a negative.
Printing Frame: A device used for contact printing that holds a negative against the photographic paper. The paper is exposed by light from an external light source.
Program Exposure: An exposure mode on an automatic or autofocus camera that automatically sets both the aperture and the shutter speed for proper exposure.
Programmed Auto: Camera sets both shutter speed and aperture for correct exposure.
Purple fringing: Chromatic aberration at microlens level.
Q
Quadtone: A printed image created with four different colors of ink.
QSIF: Short for Quartersize Image Format; an image format in which the image is reduced to 176 by 112 pixels.
R
Radial fill: A fill projected outward in all directions from a central point.
RAM: Random Access Memory, the volatile memory used to temporarily store information for processing. This is the fastest type of memory for the computer, and the most expensive. There are several types of RAM.
S-RAM: Static RAM, the most expensive type of RAM found in on-bard memory units, some Printers, and in PCMCIA Type I Cards. D-RAM, Dynamic Ram, Most often seen as the expandable RAM used by the computer for memory.
Rangefinder: Instrument for measuring distances from a given point, usually based on slightly separated views of the scene provided by mirrors or prisms. May be built into non-reflex cameras. Single-lens reflexes may have prismatic rangefinders built into their focusing screens. The Leica and the Contax G2 still keep the flag up in this areas.
Raster: A pattern of scanning for input or output, which provides uniform coverage of a two-dimensional surface, such as a monitor screen, a scanner bed, or the CCD array in a digital camera.
Rasterisation: The process of converting a graphic image to a bitmap.
RAW: The RAW image format is the data as it comes directly off the CCD, with no in-camera processing is performed.
Rear-Curtain Sync: Flash fires an instant before the second (rear) curtain of the focal plane shutter begins to move. When slow shutter speeds are used, this feature can create a blur effect from the ambient light, i.e., a flowing- light patterns following a moving subject with subject movement frozen at the end of the light flow. (See "Front-Curtain Sync".) Most mid range and top flight auto camera models have this feature.
Red-eye: The red glow from a subject's eyes caused by light from a flash reflecting off the blood vessels behind the retina in the eye. The effect is most common when light levels are low, outdoor at night, or indoor in a dimly-lit room.
Refractive index: A technical term used to describe the effect of a lens in causing light rays to bend; important aspect in lens design.
Reflector: Any device used to reflect light onto a subject to improve balance of exposure (contrast). Another way is to use fill in flash.
Reflectance: Also called reflectivity, this is the fraction of the light incident on a surface that is reflected. Reflectance varies according to the wavelength distribution of the light.
Relative aperture: Also known as the f-stop, this is the diameter of the aperture of a camera divided by the focal length of the lens.
Release-Priority: For autofocus, shutter can be released anytime (i.e., even when subject is not in focus). Helps you avoid missed opportunities when you are not concerned with absolute focusing precision, terms apply primarily for Nikon.
Reproduction ratio: Term used in macrophotography to indicate the magnification of a subject; specifically the size of the imag recorded on film divided by the actual size of the subject; for example, if the image on film is the same size as the subject, the reproduction ratio is written as 1:1 or 1X
Resample: To change the resolution of an image.
Resolution: A measure of the proportion of the smallest individually accessible portion of a video image to the overall size of the image. The higher the resolution, the finer the detail that can be discerned.
Resolution: This is the amount of information in a digitally captured image. It is measured in pixels. These are the individual elements that are like little tiles, that make up a digital image. The more of these pixels there are, the higher the resolution the picture has, and thus the more photographic the image will be. Higher resolution images can also be printed at larger sizes with more photographic results.
A high resolution camera will be capable of capturing images in the 1280x960 and above. These are sometimes referred to as "mega-pixel" cameras. That is because if you multiply the height by the width, the total is greater than 1,000,000 (a meg is one million). It means that the picture is made up of over one million pixels. This is one of the major aspects that controls the price of a camera. Generally, the higher the resolution the more the camera costs.
Many cameras usually give you the choice of at least two resolutions. A high resolution such as 1280x1024 for high resolution images, and a low resolution of 640x480. A lower resolution is handy because it allows you to get more pictures in the available memory, and will still print well at 4x6 (but not larger). The larger resolutions take a lot more room in memory, but allow for printing at sizes up to about 8x10. The larger pictures also allow liberal cropping leaving an image that can still be printed with good results.
A few cameras achieve their upper-most resolution through interpolation- that is, the camera actually can only achieve a lower resolution, and then it electronically makes the image larger. These interpolated images are usually not as sharp as a normally captured image.
Retrofocus Design: In a retrofocus design, which is advantageously applied to wideangle lenses, the back focus is designed longer than the lens' focal length to allow clearance for the movement of the reflex-mirror (No Mirror Lock up or separate viewing accessory attachment is required). It consists of front diverging apd rear converging lens groups, as opposed to the telephoto design, and is therefore also called the inverted telephoto design.
RGB: Red, Green, Blue: the three colors to which the human visual system, digital cameras and many other devices are sensitive.
ROM: Read Only Memory, used for primary instructions in many Computer Peripherals and CPU´s Firmware. There instructions can be upgraded from a computer.
S
Safelight: An enclosed darkroom lamp fitted with a filter to screen out light rays to which film and paper are sensitive. Light source consisting of housing, lamp and screen of a color that will not affect the photographic material in use. Safelight screens are available in various colors and sizes for specific applications.
Sampling rate: The number of samples obtained in a digitisation process per unit of time or distance.
Saturation: How rich the colors are in a photo.
Saturation: Also known as color purity or the amount of color density, the degree to which a color is diluted by luminance, or white light.
Saturation: The intensity, or vividness, of a color. Increasing saturation makes colors in photos look richer. The amount of saturation can be adjusted in some cameras. It can also be increased or decreased with image editing software.
Scale: To enlarge or reduce an image by increasing or decreasing the number of scanned pixels.
Scanner: An electronic input device that captures a digital image or objects into a computer.
Screen: In a camera. the surface upon which the lens projects an image for viewfinding and, usually, focusing purposes. In SLR cameras. almost universally a fresnel screen with a fine-ground surface. Often incorporates a microprism or split-image rangefinder
SCSI: Short for small computer system interface; a defined standard for the connection of mass storage and other input/output devices to a computer. A scanner or printer may employ a SCSI interface in order to communicate with a computer.
Self Timer: The self timer allows the camera to take a picture unattended. With it you can take a picture of yourself. Once the timer is set, you usually have about ten seconds to get into the picture. A flashing light or a tone signals when the picture is about to be taken.
Selective Focus: Choosing a lens opening that produces a shallow depth of field. Usually this is used to isolate a subject by causing most other elements in the scene to be blurred.
Selenium: Light-sensitive substance which, when used in a barrier-layer construction, generates electrical current when exposed to light. Used in exposure meters. Needs no external power supply.
Self-timer: Mechanism delaying the opening of the shutter for some seconds after the release has been operated. Also known as delayed action.
Semi-automatic iris: Diaphragm mechanism which closes down to the taking aperture when the shutter is released, but must be manually re-opened to full aperture.
Sensitivity: See ISO speed.
Separations: Monochrome negatives that separate the continuous colors of an image into two to four colors for offset printing.
Serial: A method for connecting an external device such as a printer, scanner, or camera, to a computer. It has been all but replaced by USB and FireWire in modern computers.
Shadow detail: These are subtle features in the darker part of an image.
Sharpen: A computer graphics process that enhances the contrast on the edges of light and dark shapes to make images appear more in focus.
Sharpness: Sometimes unprocessed DSLR images look less sharp (softer) than what a good point-and-shoot will deliver. This is not a flaw of DSLRs, but rather a choice made when programming the image processor of the camera. Manufacturers often assume that DSLR users will want to process their images with a computer and software (such as PhotoShop), and thus leave the internal processing to a minimal level. Most of the times, image parameters can be fine-tuned by the user.
Shutter: The shutter opens and closes very rapidly to control the amount of light passing through the aperture. Some cameras allow this timing to be manually adjusted. Like shutters on your window, you can only see outside as long as the shutter is open.
Shutter lag: The delay that takes place between pressing the shutter-release button and the time a photo is actually taken. Shutter lag times vary from digital camera to digital camera.
Shutter Priority: Slow the shutter in dim lit or night settings to capture more natural light (8/1 = Shutter Open 8 Seconds, 4/1 = Shutter Open 4 Seconds) and the resulting image will appear brighter. Keeping the shutter open longer may cause movement to blur, so it is best to keep the camera on a stable tripod. An example of this blur is the long red glow of taillights on a freeway at night. Speed the shutter in bright settings to freeze the action of fast moving objects (1/1000 = Shutter Open 1/1000 of a Second). An example of fast shutter action is the ability to see individual spokes on a bicycle that was racing past. During Shutter Priority Mode on Toshiba Digital Cameras the Aperture is automatically set and the Flash is disabled to optimize performance.
Shutter-release button: the shutter-release button on a digital camera must be pressed in two steps to lock exposure and focus and to help prevent camera shake.
Shutter speed: The camera's shutter speed is a measurement of how long its shutter remains open as the picture is taken. The slower the shutter speed, the longer the exposure time. When the shutter speed is set to 1/125 or simply 125, this means that the shutter will be open for exactly 1/125th of one second. The shutter speed and aperture together control the total amount of light reaching the sensor. Some digital cameras have a shutter priority mode that allows you to set the shutter speed to your liking. See also aperture.
Sidelighting: Light striking the subject from the side relative to the position of the camera; produces shadows and highlights to create modelling on the subject.
SIF: Short for Source Image Format; refers to the original image format on which the source image was taken.
Signal-to-noise ratio: The ratio of the usable signal to unusable noise in any signal. In imaging, this represents the quality of the scan.
Silicon: Light-sensitive substance which generates a minute current when exposed to light.
Single-Lens-Reflex (SLR) Camera: A type of camera that allows you to see through the camera's lens as you look in the camera's viewfinder. Other camera functions, such as light metering and flash control, also operate through the camera's lens.
Slave Strobe: If a camera does not have a flash sync socket or a hot shoe and you wish to use an auxiliary strobe light, you can get a slave strobe. This is a strobe light that has an electronic eye that senses when another strobe goes off which then sets off the slave strobe. Slave units are also available to trigger a regular strobe.
Some digital cameras need special slave strobes because they fire a pre-flash before the actual flash for the picture. This pre-flash fools the slave strobe causing it to fire before the picture is taken.
Slide scanner: The ratio of the usable signal to unusable noise in any signal. In imaging, this represents the quality of the scan.
Slow Sync: A flash technique for using the flash at a slow shutter speed. Flash shooting in dim light or at night at a fast shutter speed often results in a flash-illuminated subject against a dark background. Using a slower shutter speed with the flash brings out the background details in the picture. Use of a slow shutter speed with Rear-Curtain Sync is particularly effective for illustrating the movement of a stream of light. Can be of very creative if put to good use.
SmartMedia: a wafer-thin, matchbook size memory card. This is also a flash-memory based storage medium.
Smoothing: Also known as antialiasing, this is the electronic process of eliminating or reducing jaggies in an image.
Soft Lighting: Lighting that is low or moderate in contrast, such as on an overcast day.
Software: Operating Instructions for specific task based applications. These instructions are carried out by the computers processors. These include all packaged for use like image editing, word processing, databases, CAD, CAM, games, and so on. Software has to be written for a specific Computer OS.
Spectral sensitivity: The relationship between the radiant sensitivity and the wavelength of incident light.
Speed: A rating that determines the light sensitivity of the film; ASA (American Standards Association) and ISO (International Standards Organization) provide a standard measure by which all photographic film speeds are determined. However, all digital cameras rate their CCD's sensitivity as equal to that of a given ISO standard.
SPIFF: Short for Still Picture Interchange File Format; proposed by the ISO as a standard file format for the transfer of still images.
Split-image: Form of rangefinder image, bisected so that the two halves of the image are aligned only when the correct object distance is set on the instrument or. in the case of a coupled rangefinder, when the lens is correctly focused. SLR cameras may have a prismatic split-image system in their viewing screen. Works on the same principle as a microprism, and is restricted to apertures of f5.6 or greater.
Spot Metering: Spot metering for exposure is a method used in some SLRs and some digital cameras as well. It works like this:
There is an area marked in the optical viewfinder in the center of the image. This is the area that the camera uses to set exposure- the area of the scene that is metered. You view the scene so that the main area of the subject (such as a person's face) is in this marked area and half depress the shutter release button. This locks the exposure for that area. Now compose your shot keeping the shutter half depressed. When you fully depress the shutter release the photo is taken at that setting.
Some cameras also have spot metering for focus. In the case of the Nikon CP900 it works in conjunction with spot metering for exposure, and in some cases, such as in the Kodak DC260, it is only spot metering for focus and not for exposure. Do not confuse the two when looking at specifications.
SSFDC: This is a type of removable memory card- it stands for Solid State Floppy Disk Card (also known as "Smart Media"). It should be called "Dumb Media" because it is just a memory card with no processor. The processor is in the device that uses this type of memory card. They are convenient because they are very small, and are fairly inexpensive. They only come in 2,4,8, and 16mb sizes as of this writing.
The problem is that most all of the current devices that are on the market were designed at a time when the largest card available was 8mb. Virtually all of those devices are incapable of using anything larger than the 8mb card. It is not interchangeable with CompactFlash cards.
Stop-down metering: TTL metering in which the light is measured at the picture-taking aperture. As the meter just measures the light passing through the lens, there is no need for any lens-camera interconnections.
Stopping down: In photography, this is the process used to decrease the size of aperture in a lens.
Studio lamps (3200K): Tungsten or tungsten halogen lamps designed for studio use. Have a longer life than photo lamps, but a lower specific output and color temperature. Are used with type B films.
SQF: Subjective Quality Factor. Essentially a lens rating system.
Subtractive primary colors: Ink or other colorants, such as paint, that when combined together in equivalent amounts produce absolute black, or, when combined in different ratios, produce any color other than black.
Supplementary Lens: Generally a simple positive (converging) lens used in front of the camera lens to enable it to focus at close range. Th}e effect is to provide a lens of shorter focal length without altering the lens-film separation, thus giving the extra extension required for close focusing.
SVHS: Super Video Home system. Clearer than the conventional VHS because it separates chrominance and luminance transmission
SVGA: Short for Super Video Graphics Array; defined by IBM; represents a computer graphics adapter capable of 800 by 600 resolution.
Sync Cords: The purpose of sync cords is to allow the camera to control the flash, so the flash fires at the correct time. Other common names for electrical cords to connect flash to camera are PC cord, sync cord and synch cord. One type of electrical connector on camera bodies is called a PC socket, whence the name, PC cord. Sync and synch are both intended to be abbreviations of the word synchronization.
Sync Delay: All electronic flash units require X sync, but flashbulbs require a time delay between firing the flash and opening the camera shutter. The optimum delay varies among flashbulb types, but you will get much of the flashbulb light through the shutter and onto the film even if delay is not exactly correct. Firing delay for flashbulbs is indicated by code letters:
"F"- fast; "M"- medium; "MF" - mediurn fast; "S" - slow
Sync Socket: Often called "PC terminal" or "PC Socket". Most older manual focus SLR camera bodies have this standard PC sockets which have a threaded collar surrounding the center electrical part of the socket. Some older flash units may not have a hot shoe on the flash unit and would need cable connection to fire the flash (sync) timely with the shutter. Some flash cords have a connector that makes electrical contact with the center part of the socket and is held securely in place by a threaded ring which screws into the outer part of the socket on the camera body. It is also use for multiple flash setup (non-TTL or manual) where the secondary flash can be used via a sync cord to fire at the same time.
Sync speed: Exposure time with a focal-plane shutter is measured from the instant the first curtain is released, to begin its travel across the frame, until the instant the second curtain is released, to begin its travel across the frame. When the first curtain reaches the end of its travel, the film frame is uncovered as far as the first curtain is concerned, so it closes the electrical contacts for X sync and fires the flash instantly. Shutter speed at which the entire f iIm frame is exposed when the flash s fired in flash shooting. Most modern camera with vertical travel shutter curtain have faster flash sync speed like 1/250 sec. or slower, some top camera model like Nikon F5, changeable to 1/300 sec. with the Custom Setting.
Synchronisation: Concerted action of shutter opening and closing of electrical contacts to fire a flashbulb or electronic flash at the correct moment to make most effficient use of the light output. Roughly speaking, FP or M-synchronisation is constructed to fire flashbulbs just before the shutter is fully open, allowing a build-up time, and X-synchronisation fires electronic flash exactly at the moment the shutter is fully open.
System palette: A color palette chosen by a computer system and applied to all digital images.
T
T (setting): Setting that holds the camera shuttle open until the shuttle dial is turned or release is press the second time. This setting differs from "B" (Bulb) that it usually is a stand alone setting and never drains the battery power and thus ideal for really long time exposures.
TGA: Short for True Vision Targa File; a storage format for bitmapped video images.
Telephoto Lens: You can think of telephoto as the opposite of wide angle. This is the range from about 55mm and above. Film cameras can have lenses that range up to and above 1,000mm. With digital cameras, most only go to about 115mm. It is like using a pair of binoculars or a telescope.
Third-party lenses: Some lens manufacturers design the optical elements of a lens, then adapt the design to fit on the various mounts of the most common brands. The three best known third-party manufacturers are Sigma, Tamron and Tokina, but there are others. Some brands license their communication protocols to third-party manufacturers, but not all, which means that sometimes reverse engineering is necessary for third-party manufacturers to make lenses communicating with a camera. Third-party lenses can be just as good as original brand lenses, and often equal-quality lenses will be less expensive when purchased from third-party manufacturers.
Threaded Lens: Some cameras allow the addition of additional lenses to increase the telephoto range or allow greater magnification for macro work. The most convenient way to add these accessory lenses is by means of a threaded lens. The end of the lens housing has threads that these other lenses can thread into, or onto which an adapter can be attached to accept the accessory lenses.
Thumbnail: A small version of a photo. Image browsers commonly display thumbnails of photos several or even dozens at a time. In Windows XP's My Pictures, you can view thumbnails of photos in both the Thumbnails and Filmstrip view modes.
TIFF: Short for Tagged Image File Format; a computer graphics file format developed by Aldus, Adobe, and Apple. Tagged Image File Format (TIFF) is an industry standard raster file format, which consists of the image and header information. TIFF is also supported by most desktop publishing and paint programs.
Transmittance: The fraction of the incident light that passes through an object.
Tritone: A printed image created with three different colors of ink.
Through-the-lens (TTL): Type of exposure meter built into the camera body and reading through the camera lens. May measure either at full aperture or at picture taking aperture. (refer below for more descriptions).
Through-The-Lens Focusing: Viewing a scene to be photographed through the same lens that admits light to the film. Through-the-lens viewing, as in a single-lens-reflex (SLR) camera, while focusing and composing a picture, eliminates parallax.
Through-The-Lens Metering: Meter built into the camera determines exposure for the scene by reading light that passes through the lens during picture-taking. Most SLR cameras have built-in meters which measure light after it has passed through the lens, a feature that enables exposure readings to be taken from the actual image about to be recorded on film, whatever the lens angle of view and regardless of whether a filter is used or not.
Time Exposure: A comparatively long exposure made in seconds or minutes.
Tint: Shades of white in a finished print, controlled by the color of the paper, varying from white to buff.
Titanium/Titan Camera Body: Titanium is one of the world's strongest, yet lightest materials; its specific grauit is approximately half that of brass, yet its hardness is almost the same as that of steel, while its corrosion resistance is greater than that of stainless steel. However, titanium is a uery difficult material to process.
TLR: Twin lens reflex camera that have separate viewing and actual exposure lens. Rollei still have one in production.
Tone: The degree of lightness or darkness in any given area of a print; also referred to as value. Cold tones (bluish) and warm tones (reddish) refer to the color of the image in both black-and-white and color photographs.
Toning: Intensifying or changing the tone of a photographic print after processing. Solutions called toners are used to produce various shades of colors.
Transparency: Basically, slide film. A positive photographic image on film, viewed or projected by transmitted light (light shining through film).
Transparent magnetic layer: Information storage layer built into Advanced Photo System film that enables enhanced information exchange capabilities, improving print quality by capturing lighting and scene information and other picture-taking data; basis for future information exchange features.
Tripod: A three-legged supporting stand used to hold the camera steady. Especially useful when using slow shutter speeds and/or telephoto lenses. Another is the monopod, single leg tripod.
True color: A term used to describe an image that has a bit depth similar to the response of the human eye and which is considered to represent color as seen through the human eye.
T/S: The tilt and shift lens, Canon's version of the PC (perspective control) lens.
TTL auto flash: The camera's light sensor measures flash illumination, as reflected by the subject on the film and shuts off the flash where measurement indicates a correct exposure. Because the sensor that controls the flash receives light through the lens TTL auto flash can be used for bounce flash photography, fill flash, multiple flash photography, etc. An additional advantage of TTL auto flash is that it enables you to use a wide range of aperture settings, while ensuring correct exposure.
Tungsten Light: Light from regular room lamps and ceiling fixtures, not fluorescent. Images produced under this light source can be extremely warm, in fact excessive warmth. Need some color balance filtration or flash to neutralise that.
Twain: A programming interface that lets a graphics application, such as an image-editing program or a digital camera, activate a scanner, a frame grabber, or another image-capturing device.
Twain: An acquire interface developed by a consortium of software developers as a standard for communications between scanners, imaging devices and now digital cameras and other and the computer software. Twain allows you to import (acquire) an image into your software. This is the interface of choice on the Window´s platform .
U
UCR: Short for undercolor removal; reducing the cyan, magenta, and yellow inks from the darkest neutral shadow areas in an image by replacing them with black ink.
UD: Ultra Low dispersion lens, pls refer to ED, LD sections.
Ultra-wide angle lens: Extra-wide angle lens, usually those with an angle of view greater than 90°. For 35 mm cameras the description usually applies to lenses of shorter focal length than about 24 mm.
Underexposure: Improper exposure causing an image to look too dark. There is a loss of detail in dark areas.
Under Exposed: An under exposed picture means that too little light was allowed to strike the film (or the proper amount of light was allowed to strike the film for too short a period of time). That means that the aperture was too small for the exposure time, or the exposure time was too short for the aperture opening. This will give an image that is too dark.
Unipod: Also refer as monopod.A one-legged support used to hold the camera steady. Also see "tripod".
USB: Universal Serial Bus: a protocol for transferring data to and from digital devices. Many digital cameras and memory card readers connect to the USB port on a computer. USB card readers are typically faster than cameras or readers that connect to the serial port, but slower than those that connect via FireWire.
UV: The ultra violet ray. This is beyond the visible spectrum i.e. it's invisible electromagnetic radiation of the sunlight. UV lenses is very expensive, only Nikon has a offering in its Nikkor lens line.
V
Value: The relative lightness and darkness of a color or tone.
Variable-Contrast Paper: Photographic paper that provides different grades of contrast when exposed through special filters.
Variable focus lens: Lens of which the focal length can be continuously varied between set limits. The lens must be refocused with each change in focal length.
Vector: An electronic or computer-readable image format incorporating a formulate representation of graphical line art. Vector format is used during the markup process, to keep redlines separate from images and to facilitate easy modifications. This format is also often used during the edit process.
VGA: Short for Video Graphics Array; defined by IBM; represents a computer-graphics adapter capable of 640 by 480 resolution. Also see SVGA.
Video digitiser: Also called a frame-grabber, this is an image capture device that employs a video camera attached to a circuit board in a computer, which converts the video signal into a digital file.
Video Output: Some cameras have an outlet built-in that allows the user to attach a cable from the camera to a VCR or other video device that accepts NTSC (on in Europe, PAL) video signals. The camera can then show its pictures on the television screen. This can be used to look at the images without a computer for a slide show or presentation. Images can also be saved on video tape to be sent to people who do not have computers, or used as presentations.
Viewfinder: An optical or electronic display used to frame an image in the camera. One looks through the viewfinder in order to see the image that will be captured by the camera.
Vignetting: Underexposure of image corners produced deliberately by shading or unintentionally by inappropriate equipment, such as unsuitable lens hood or badly designed lens. A common fault of wide-angle lenses, owing to reflection cut-off, etc. of some of the very oblique rays. May be caused in some long-focus lenses by the length of the lens barrel.
Visible light: The portion of the electromagnetic spectrum that the human eye can see, bordered on the "red" end by infrared, and on the "blue" end by ultraviolet.
VRAM: Short for video random access memory; a special high-speed type of RAM that is used temporarily to store visual information being transferred to the display hardware in a computer.
W
Watermark: These are bits altered within an image to create a pattern that indicates proof of ownership. Unauthorised use of a watermarked image can be traced.
White balance – A function on the camera to compensate for different colors of light being emitted by different light sources.
White balance: Adjusts the brightest part of a scene so it appears white. How a digital camera records color is affected by the source of light.
White Balance: This is the ability of the camera to adjust the color balance of a picture to compensate for the ambient lighting. It is easy to see that flourescent lights have a different color from incandescent lights. These are both different from the light that a photo flash gives off, and they are all different from the color of the light from the sun. This is often adjusted automatically in digital cameras, and it makes picture taking easy. If a camera possesses this function it is said to have "auto white balance."
AWB - Automatic White Balance: A system for automatically determining white balance. When brightness changes, the human eye adapts so that a white object still looks white. On the other hand, devices such as digital still cameras see a white subject as white by first adjusting the balance to suit the color of the ambient light around the subject. This adjustment process is referred to as matching the white balance.
Wide-angle lens: A lens that has an angle of view greater than that of a standard lens and that is considered of short focal length. This kind of lens is usually employed to include more of a subject within the confines of the image frame.
WS: Watt per second. For flash mode, the measurement of electrical energy in the flash.x
WYSIWYG: Short for what you see is what you get, this term refers to the graphical interface that allows you to see
onscreen what you will be able to print.
X
X (setting): Electronic flash units fire virtually instantaneously and reach full brightness immediately. Therefore no time delay is required. Also refer as X sync. Real time setting that causes the flash to burst in synchronises or instantaneously as the shuttle open up. For older manual camera, the X synch speed usually refers to the maximum speed that the camera can have its shuttle curtain open long enough to synchronise with the flash. In fact, if there is a time delay, the electronic flash may be all over before the shutter gets open. To fire electronic flash with a focal-plane shutter, the switch in the camera is closed at the instant the first curtain of the focal-plane shutter reaches fully open-called X synchronization.
X Sync Terminal: Electronic flash units are available which mount on the hot shoe and are triggered by the electrical contact in the shoe. Other types use sync cord which connects to the sync terminal on the camera. also referred to PC Terminal section.
Z
Zoom Lens: Some lenses have the ability to change their magnification level through a range of focal lengths (wide angle through telephoto). This is called a zoom lens as is seen on most all camcorders. With digital cameras the range varies by brand and model, but ranges in the area of 35mm to 115mm are fairly common. This range would often be referred to as "3X" (three times) zoom (3x35=105, so the telephoto setting is about 3 times the wide angle setting). The best cameras achieve this by moving various elements in the lens. This would be referred to as optical zoom. Cameras using optical zoom are generally larger than those without because of the more complicated and thus larger lens elements.
Recent Posts
- Gaming And Beyonf With The PS3 Console
- Freelance Photography Jobs – Sell Your Photos
- Applying Make-Up For Photography
- Memorable Christmas Pictures With A Digital Camera
- Considering Discount LCD TVS
- Finding The Perfect 3 Stone Diamond Ring
- A Few Suggestions To Make Moving You’re your Residence Hall Easier
- My Traffic Business-Affiliate Marketing Fundamental Principle
Categories
- Action Photography
- Digital Camera Reviews
- Digital Cameras
- Digital Photography Tech
- Digital Photography Tips
- Freelance & Professional Photography Jobs
- Hobbies
- Lighting
- Nude Photography
- Photography
- Portraiture
- Technology and Gadgets
- Wedding Photography
Links
Tags
