ABC - 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 recognises 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 reat 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.

Abbe number - denotes the degree of refraction of light of different wavelengths to different extents, given by a transparent material, such as glass. The lower the Abbe number, the greater the dispersion of colors.

Aberration - the inability of a lens to produce a perfect, sharp image, especially towards the edge of the lens field. These faults can be reduced by compound lens constructions, and the use of small apertures.

Abrasion marks - marks on the emulsion surface of a film, caused by scratching. It can be due to traces of dirt trapped between layers of film as it is wound on the spool, or to grit on the pressure plate.

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" lense 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 lense 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 lense 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 lense 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 lense. 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.

Absolute released images - any images for which signed model or property releases are on file and immediately available.

Absolute temperature - the temperature at which most molecular movement ceases. It is often referred to as absolute zero (-273° C).

Absorption - the process by which light falling on a surface is partially absorbed by the surface.

Abstract - subjective, non-realistic image. An abstraction photograph generally contains a design of patterns or shapes where the identity of a subject is not evident.

Accelerator - chemical added to a developing solution to speed up the slow working action of the reducing agents in the solution.

Acceptable Circle of Confusion - the size of the largest circle which the eye cannot distinguish from a dot. In 35mm format cameras, a 0.03mm diameter circle of confusion is considered acceptable. It is used to calculate depth-of-field or depth of focus.

Acceptance angle - see Angle of View.

Accessory shoe - metal or plastic fitting on the top of the camera which supports accessories such as viewfinder, rangefinder, or flash gun.

Acetate base - non-inflammable base support for film emulsions which replaced the highly inflammable cellulose nitrate base.

Acetic acid - chemical used for stop baths and to acidify acid fixing solution.

Acetone - solvent chemical used in certain processing solutions that contain materials not normally soluble in water.

Achromatic - lens system that has been corrected for chromatic aberration.

Acid - chemical substance with a pH value below 7.

Acid fixing solutions - solutions which contain an acid to neutralize any carry-over of alkaline developer on the negative or print.

Acid hardener - substance used in acid fixer to help harden the gelatin of the emulsion.

Acid rinse - weak acid solution used after development and before fixation. By neutralizing alkaline developer left on the photographic material it arrests development.

Actinic - the ability of light to cause a chemical or physical change in a substance.

Actinometer - early type of exposure calculator.

Acuity - subjective term for the visual sharpness of an image.

Acutance - objective measurement of image sharpness.

Adapter ring - circular mount, available in several sizes, enabling accessories such as filters to be used with lenses of different diameters.

Additive color - see Additive Printing.

Additive printing - color printing method which produces an image by giving three separate exposures, each filtered to one of the three primary color wavelengths, blue, green and red.

Additive synthesis - method of producing full-color images by mixing light of the three primary color wavelengths, blue, green and red.

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 enbodied 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.

Aerial perspective - the distance or depth effect caused by atmospheric haze. Haze creates a large amount of extraneous ultra-violet light to which all photographic emulsions are sensitive.

AF lock - stops autofocus operation once the subject is in focus. Useful when shooting a subject outside the focus area in the viewfinder. The photographer should first lock the focus with the subject inside the focus area, then recompose the shot as neccesary.

Afocal lens - lens attachment that alters the focal length of the camera lens without disturbing the distance between the lens and the film plane.

AF Sensor - the sensor used to detect focus.

Aftertreatment - the treatment of negatives and prints to correct certain faults in exposure and development, or to create special effects.

Agitation - method by which fresh solution is brought into contact with the surface of sensitive materials during photographic processing. 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.

Air bells - bubbles of air clinging to the emulsion surface during processing.

Air brushing - method of retouching b&w or color photographs where dye is sprayed, under pressure, on to selected areas of the negative or print.

Air-to-air photography - photography of aircraft in flight from another aircraft.

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.

Albert effect - effect that creates a reversed image. An exposed frame of film, treated with dilute chromic acid is exposed to light. Development then gives a positive image by darkening the film grains that were not initially affected by exposure.

Albumen paper - printing paper invented by Blanquart-Evrard in the mid-19th century where egg whites were used to coat the paper base prior to sensitization. The albumen added to the brightness of the white base and substantially improved printed highlights.

Alcohol thermometer - instrument used for measuring temperature. It is an inexpensive and less accurate version of the mercury thermometer.

Alkalinity - denotes the degree of alkali in a solution, measured in pH values. All values above pH 7 are alkaline.

Allegory - work of art that treats one subject in the guise of another. An allegoric photograph usually illustrates a subject that embodies a moral "inner meaning".

Alphabetical Coding - Some early lenses such as Nikon and Olympus uses some alphabetical coding to illustratre the composition of their lenses. Fora na exmaple, 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 lense: "S": Standard, "W"=Wide Angle and "T"=Telephoto. While another example:
U (Uns) for 1 lense 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

Alum - chemical used in acid hardening fixing baths.

Aluminum compounds - groups of chemicals often used as hardeners in fixing baths.

Ambient light - the available light 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.

Ambrotype - Mid-19th century photographic process introduced in 1851-52 by Frederick Scott Archer and Peter Fry. It used weak collodion negatives which were bleached and backed by a black background which produced the effect of a positive image.

Amidol - soluble reducing agent which works at low pH values.

Ammonium chloride - chemical used in toners and bleachers.

Ammonium persulfate - chemical used in super-proportional reducers.

Ammonium sulfide - pungent but essential chemical in sulfide or sepia toning.

Ammonium thiosulfate - highly active fixing agent used in rapid fixing solutions which works by converting unused silver halides to soluble complexes.

Amphitype - Mid-19th Century process based on an underexposed albumen-on-glass negative. This was viewed by reflected light against a black background to give a positive image similar to a ambrotype.

Anaglyph - result of forming stereoscopic pairs from two positives each dyed a different color, usually green or red.

Analyzer - chart, grid or electronic instrument used to determine correct color filtration when making color prints.

Anamorphic lens - lens capable of compressing a wide angle of view into a standard frame.

Anastigmat - compound lens which has been corrected for the lens aberration "astigmatism".

Angle of incidence - when light strikes a surface it forms an angle with an imaginary line known as the :normal," which is perpendicular to the surface. The angle created between the incident ray and the normal is referred to as the angle of incidence.

Angle of view - is the maximum angle of acceptance of a lens which is capable of producing an image of usable quality on the film. 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 lense 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 lense. All objects within this angle will be recorded by the lense on the film.

Angstrom - unit of measurement used to indicate specific points of wavelengths within the electromagnetic spectrum. Visible light rays occur between 4000 - 7000 Å.

Angular field - the angle subtended at the lens by the diameter of the largest circle within which the lens gives an image of acceptable sharpness and even illumination.

Anhydrous - dehydrated form of chemical. More concentrated, so that less weight is needed in a formula than the crystalline kind.

ANSI - speed rating system for photographic materials devised by the American National Standards Institute.

Anti-fogging agent - constituent of a developer that inhibits or reduces fogging during development.

Antihalation backing - dye used on the back of most films capable of absorbing light which passes straight through the emulsion. In this way it reduces the amount of extraneous light that can be reflected from the camera back through the emulsion.

Antinous release - alternate term for a camera cable release.

Antiscreen plates - photographic plates containing dyes that reduce the blue sensitivity. Used unfiltered, they can give results similar to those obtained with yellow filtered orthochromatic plates.

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 colours of the visible spectrum to a common plane of focus, within close tolerances, usually refer to a lens with such superior colour correction. Also refer to "ED", "LD", "SD", "UD".

Aperture - Lens opening. The hole or opening formed by the metal leaf diaphragm inside the lens or the opening in a camera lens through which light passes to expose the film. The size of aperture is either fixed or adjustable. Aperture size is usually calibrated in f- numbers-the larger the number, the smaller the lens opening. Aperture affects depth of field, the smaller the aperture, the greater is the zone of sharpness, the bigger the aperture, the zone of sharpness is reduced. The hole or opening formed by the metal leaf diaphragm inside the lens; controls amount of light and depth of field, prevents vignetting and reduces lens aberrations; the size of the aperture is indicated by its f-number, i.e., the ratio of the diameter of the opening to the focal length of the lens; a large aperture is indicated by a small numerical f-number.

Aperture priority camera - 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 - 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.

Aplanat - lens which has been corrected for spherical aberration.

Apochromat - lens corrected for chromatic aberration in all three primary colors.

APO (Apochromatic) - the ability to bring all colors of the visible spectrum to a common plane of focus, within close tolerances. It usually refers to a lens with such superior color correction.

Apodization - lens treatment designed to cut down diffraction fringes that appear around the images bright points of light.

APS (Advanced Photo System) - consumer photography developed by Kodak and four other companies - Canon, Fuji, Minolta and Nikon . It is based on a new film format and photofinishing technologies.

Aquatint - etching technique allowing control of tonal areas to produce almost unlimited gradations from pale gray to black. Because of this it has also been used in photography as an alternative term for gum bichromate process.

Archival permanence treatments - various treatments given to prints to make them fade-resistant.

Arc lamp - photographic lamp in which light is produced by passing an electric current through two carbon rods.

Argentotype - Mid-19th century silver print process, on which the kallitype and sepia paper processes are based.

Aristotype - early commercial print type made on collodion-chloride or gelatin-chloride paper.

Artificial daylight - artificial light having a similar color temperature to daylight.

Artificial light - all light not originating from a natural source - normally the sun.

Artificial light film - color film balanced for use ion tungsten Artificial light, usually 3200 K.

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 Organisation).

Aspect ratio - ratio of width to height in photographic prints. The ratio is 2:3 in 35 mm pictures which produces photographs most commonly measuring 3.5 x 5 inches or 4 x 6 inches.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. See also Interspersed Aspect Ratio. The Advanced Photo System's three user selectable print formats: "C" - 2:3 aspect ratio used in 35 mm photography "H" - 9:16 aspect ratio used by high-definition television (HDTV) "P" - 1:3 aspect ratio produces prints of 3.5 x 10.5 inches or up to 4.5 x 11.5 inches; suitable for panoramic shots

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.

Aspherical surface - lens surface with more than one radius of curvature, i.e. the surface does not form part of a sphere.

Assembly printing - method of printing using image separations. Yellow, magenta, and cyan films are stacked to make a final, full color print. Assignment - definite OK to take photos for a specific client with mutual understanding as to the provisions and terms involved.

Astigmatism - lens aberration making a single point light source impossible to focus as a true point.

ATA - term used to describe a camera, which 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. 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.

Atmospheric perspective - alternative term for aerial perspective.

Audiovisual - materials such as filmstrips, motion pictures and overhead transparencies which use audio backup for visual material.

Autochrome - early commercial color photography process in which the principles of additive color synthesis were applied.

Autofocus - 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 popularised with the launch of Minolta's Maxxium. Currently, most current SLRs are autofocus based.

Automatic aperture - lens aperture mechanism that stops down to s preset size just as the shutter is fired, afterwards returning to the maximum aperture again for focusing and composing the next image.

Automatic exposure control - system of exposure setting in a camera, in which the electric current produced or inhibited by the action of light on a photoelectric cell operates a mechanism that adjusts the aperture and/or the shutter speed automatically.

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.

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 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.

Automatic lens - lens which remains at full aperture whatever working aperture is set, until the shutter is released. This allows optimum focusing, without affecting metering. Also referred to as Automatic aperture.

Autowinder - film wind-on mechanism which moves the film on one frame each time the shutter is released.

AV - see Audiovisual. (The Aperture value, usually refer to aperture settings.)

Available light - term applying to light normally occurring in a scene, not supplemented by illumination intended specifically for photography.

Axis lighting - light pointed at the subject from a position close to the lens.

Azo dyes - compounds forming colors of great strength and purity. Used in camera filters and integral tripack dye -bleach materials.