|A or Av
||Aperture priority or Aperture value. Automatic exposure mode where the photographer sets the lens f-stop and the AE firmware sets the shutter speed.|
||Automatic exposure. Hardware and software ("firmware"), built into the camera, measures luminance of the subject and automatically sets shutter speed, lens aperture or sensitivity, this also allow camera to set the aperture for manual lenses fixed with this AE chip.|
|AE-L or AEL
||Automatic exposure lock. Technology for holding an exposure setting from one scene to another.|
||Autofocus. The lens is focused automatically by means of the camera's hardware and firmware, to obtain optimum sharpness of an image.|
|AF-L or AFL
||Autofocus lock. Locks a particular focus setting, preventing refocusing if the scene changes.|
||Angle of view. Describes the angular extent of a given scene that is imaged by a camera.
||Additive system of photographic exposure. A system to aid calculation of correct exposures, developed in the 1960s. Some aspects are included in Exif.|
||A film format defined by the Advanced Photo System as 25.1 × 16.7 mm. Different manufacturers use this term for image sensors measuring between about 20.7 × 13.8 mm to 28.7 × 19.1 mm. This format has an approximate ratio of 1.5 : 1.
||The American Standards Association (now called the American National Standards Institute, ANSI) defined the ASA system for rating the speed sensitivity of photographic emulsions; now superseded by the ISO system.|
||Automatic white balance. A setting that uses the camera's hardware and firmware to estimate the colour temperature of the scene.|
||Chromatic aberration. Failure of a lens to focus all colours at the same point. The aberrations can be along the optical axis (Longitudinal CA, or LoCA) or off-axis (Lateral or Transverse CA, TCA).|
||Charge-coupled device. A semiconductor technology, used to create photosensor arrays for some digital cameras.|
||Camera left. Similar CR is camera right, slang in photography groups
||Catch in focus. A technique for allowing a camera to be pre-focussed to a defined spot, and the exposure is only made when a subject is in focus at that spot. Also called trap focus.
||Complementary metal oxide semiconductor. A semiconductor technology, used to create photosensor arrays for some digital cameras.|
||CMYK color model. A subtractive process for color printing that utilises cyan, magenta, yellow and black inks to create most printable colors. (Some colors can not be accurately reproduced using this system and require the use of "spot color" to be used. See also: Pantone Matching System.) Some other printable colors can be reproduced using Hexachrome color model which adds orange and green to the base CMYK color model. (CMYKOG) It is possible to omit black ink, in which case the process is termed CMY.|
|CP, CPL, or CPoL
||Circular polarizing filter.
||Compact system camera. Mirrorless interchangeable-lens camera, smaller than a digital single-lens reflex camera.
||Design rule for Camera File system. A digital camera file system standard; JEITA number CP-3461.|
||Deutsches Institut für Normung. A logarithmic system for expressing film speed in common use in Europe since 1934. Now combined with the ASA linear system, in the form of the ISO system.|
|DOF or DoF
||Depth of field. A measure of the permissible distance within which an object remains in acceptable, though not perfect, focus. Calculations of DOF assume that an imperfectly focused "circle of confusion" smaller than 0.20 to 0.25 mm is indistinguishable from perfect focus in an image viewed from a normal distance. This is approximately equivalent to 0.03 mm in the case of an image on 35 mm film or FF format.|
||Dots per inch. A measure of the ability of a printer or scanner to handle fine detail.|
||Dynamic range. Expresses the luminance range of a scene, a captured image or the maximum range of luminance that a camera can successfully capture at one setting. It is often used imprecisely, but can sometimes be quantified as a ratio. The term contrast ratio may be preferred for the luminance range in a scene.|
||Digital Still Camera. Prefix on image filenames produced by various digital cameras.
||Digital single-lens reflex camera; also dSLR.|
||Extra low dispersion glass. Used in composite lenses to reduce chromatic aberration. One of a class of special glasses, including anomalous dispersion (AD), special low dispersion (SLD) and extraordinary low dispersion (ELD) glass, used in place of fluorite.|
|EFC, EFCS or EFSC
||Electronic first curtain, electronic front curtain, electronic first curtain shutter, electronic first shutter curtain of a focal plane shutter.
||Exposure value. A system for indicating correct exposure in which the shutter speed and f-number are related arithmetically.|
||Electronic viewfinder. The through-the-lens view is displayed on a miniature solid-state screen, rather than on an optical screen or view.|
||Electronic viewfinder interchangeable lens camera. See also MILC, mirrorless interchangeable-lens camera.|
||Exchangeable image file format. A standard format for tag data in digital camera files.|
||f-number, f-stop. The numerical value of a lens aperture. The ratio of the focal length of the lens divided by its effective aperture diameter.|
||Full frame, where the image sensor is approximately the same size as a 35 mm film: 36 × 24 mm.
||Focal plane. A shutter that opens and closes near to the film or image sensor, usually as a fast-moving slit, as contrasted with a bladed/leaf shutter located near a nodal point of a lens.|
||Focal plane array. A matrix of sensors positioned in the focal plane of a lens or other focusing device.|
||Frames per second. Used in reference to maximum continuous shooting rate or video.|
||Graphics Interchange Format. A computer file format for coloured images, restricted to 256 colours and useful for small file-size.|
||Guide number. A value indicating the power of an electronic flash apparatus, and used to estimate exposure. GN = distance × f-number. One needs to specify the film or sensor ISO speed, and it is conventional to quote for ISO 100/21°. The distance can be in feet or in metres, the units to be specified.|
||Graduated neutral density. A type of neutral density filter in which brightness is reduced more on one side of the filter than on the other, allowing the photographer to reduce the contrast between, for example, bright sky and dark land.
||High dynamic range. Techniques that allow a digital image to show a wider contrast range than current image sensors can record in one file. Some cameras have firmware to do the processing.|
||Intentional camera movement. The camera or the focus or zoom of its lens is adjusted by the photographer during an exposure in order to achieve special or artistic effects.
||Image quality. An informal abbreviation used in discussion forums. Usually subjective, though some studies have analysed mathematically quantifiable components of image quality.|
||Infrared. The electromagnetic radiation with wavelengths longer than about 700 nm and not visible to the human eye.|
||Image stabilization. Technology to minimize image blurring by camera movement during exposure. See also AS, OS, OIS, OSS, SR, SS, SSI, SSS, VR as brand-specific terms.|
||A system for quantifying the sensitivity ("speed") of a photographic emulsion, or a solid-state digital-camera's image sensor, to visible light. Normally followed by a numerical value, e.g.: ISO 100 or ISO 64/19°. Developed from the ASA and the DIN systems by the International Organization for Standardization.|
||A format designed by the Joint Photographic Experts Group, that allows files of coloured images to be compressed to a smaller digital file than if the full range of colours were to be saved. Also .JPG as a computer file extension.|
||Lens buying addiction. Usually used in a jocular sense on camera forums, about a wish to add to an already extensive collection of interchangeable lenses.
||An ambiguous abbreviation that should be avoided. Some writers use it to mean lateral (transverse) chromatic aberration, TCA, while others use it to mean longitudial (axial) chromatic aberration, LoCA.
||Liquid crystal display. A technology often used in the monitor screens of digital cameras, etc.|
||Light-emitting diode. Semiconductor technology to convert electrical energy into light efficiently. Quasi-white and a range of colours, as well as infrared are possible.|
||Longitudinal (axial) chromatic aberration.|
||Lightroom, a popular software application for processing images from digital cameras. Developed by Adobe.|
||Multi-coating or multi-coated. Anti-reflection coating of lenses to reduce transmission losses. May also stand for meter coupling or meter-coupled lenses. Whilst being a generic term, the designation in the latter meaning is mostly used to describe a generation of Minolta SR-mount lenses implementing this feature.
||Manual focus. The photographer adjusts the lens to obtain the image sharpness required, as opposed to AF. Alternative meaning: Medium Format. A size of film or image sensor somewhat larger than the 35mm film standard of 36 × 24 mm.
||Mirrorless interchangeable-lens camera. Similar to a digital single-lens reflex camera, but having an electronic or rangefinder type of viewfinder in place of the mirror and pentaprism, to allow a more compact design. See also EVIL camera.
||Modulation transfer function. A technical measure of the ability of a lens to create a finely detailed image. Several types of specialized apparatus are available to get the basic data on a lens and to analyse it. The calculated performance may be presented in various ways.|
||Neutral density. A neutral-grey pre-lens filter to reduce overall brightness without altering colour balance.|
||Noise reduction. Digital noise reduction through firmware processing or editing the digitized image.
|OOF or OoF
||Out of focus, Out of Frame.
||Optical viewfinder. The picture is framed on the focusing screen of a through-the-lens optical viewfinder, as found on [D]SLR cameras, or in a look-through-viewfinder, as found on rangefinder cameras.
||Prontor-Compur. A 3.5 mm coaxial camera jack named PC terminal, to synchronize external non-dedicated flashes (f.e. studio flashes), found on many more advanced camera models. Also may mean "Perspective Control" for a lens that has the ability to shift to tilt to control linear perspective in an image. May also stand for personal computer in conjunction with digital photography.
||Purple fringing. A form of chromatic aberration in which a purple-violet haze degrades high contrast edges or over-saturated highlights. Some models of lens are widely criticised for this fault, though there are suggestions that it might also be due to properties of digital sensors.|
||Portable Network Graphics. A computer file format for compressed coloured images useful for small file-size.
||Point-and-shoot camera. Photographers' slang for a small or compact camera that is easy to use because the essential functions are automated. Popular, but with limitations compared with more advanced cameras such as DSLR cameras with larger image sensors.
||PixelsPerInch. The number of pixels or picture elements contained in one linear inch in a digitally stored image.
||Photoshop, Photoshop Elements. Commercial computer applications developed by Adobe for editing digital images.|
||RGB color space. An additive colour space that uses the primary colours of red, green and blue to create any colour. There are several variants: sRGB, ISO RGB and some proprietary standards. Used mainly in colour displays: computer monitors, digital cameras, etc.|
||Resolving power. Usual meaning is the reciprocal of the distance between two just-distinguishable subject details.|
|S or TV
||Shutter priority or time value. Automatic exposure mode where the photographer sets a shutter speed, and the AE firmware automatically sets the appropriate lens aperture.|
||Soft Capture. Capture of light emitting objects as the primary subject with light quality that is not primary but equally soft or washed as the background.|
||Single-lens reflex camera. A camera where the same lens is used to view the scene and to focus its image onto a film emulsion or solid-state photosensor. Usually combined with the facility to fit one of a range of lenses, and often more versatile than viewfinder/rangefinder cameras.|
||Straight out of camera. Images as shot out of camera; implied is no post processing, slang in photography groups
||Shoot through umbrella. White translucent photographic umbrella; a flash is shot inside the umbrella and the light is diffused onto the intended target; provides a soft, large light source.
||Sensitivity value. Sensitivity priority automatic exposure mode, where the photographer sets the ISO sensitivity and the AE firmware sets the aperture or shutter speed.
||Teleconverter. A lens accessory that fits between the lens and camera body and extends the focal length of the lens, often by 1.4x or 2x, at the cost of reduced light, decreased image quality, and slower autofocus.
||Transverse (lateral) chromatic aberration or lateral colour. Colour fringes that worsen the further the image point is from the optical axis.|
||Tagged Image File Format. A high fidelity computer file format for handling digital images that does not sacrifice colour and form detail in the way that 'lossy' compression formats such as GIF, JPEG and PNG do.|
||Twin-lens reflex. A camera with two lenses, one for taking pictures and one for viewing the scene. The two lenses are typically linked to ensure that they remain focused at the same distance.
||Through the lens. Through the lens metering measures the luminance after it has passed through the camera lens, thus providing readings or settings that allow for aperture and focus changes, filters, etc.|
||Ultraviolet. The electromagnetic radiation with wavelengths shorter than about 400 nm and not visible to the human eye.|