photo laureates offers you an index of key photography terms in photography

Ambient Light
See Available light

Angle of view
The amount of subject included in the picture. Expressed as the angle made between lines drawn to the camera from the two extremities (opposite corners) of picture contents. Wide-angle lenses have a wider angle of view than telephoto lenses.

Aperture
Circular hole in front of or within a lens that restricts the amount of light passing through the lens to the photo laureates material. On the majority of lenses the size of the aperture can be varied, and controlled by an iris diaphragm. This can be set to a series of "stops" calibrated in f numbers by rotating an external ring.

Aperture preview
Looking at the image with the aperture stopped down to the setting you intend to use when taking the picture. Allows visual assessment of depth of field.

Aperture-priority mode
Semi-automatic camera exposure system in which the user selects the aperture, and the camera meter then automatically sets the shutter speed.

ASA
American Standards Association. denotes a speed system with which manufacturers may "rate" their film in terms of its sensitivity to light. Now superseded by ISO.

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

Backlighting
Artificial or natural lighting coming toward the camera from behind the subject.

Bellows
Concertina-type folding fabric tube that fits between lens and SLR camera body. Allows continuous forward extension of the lens when focusing very close subjects.

Bracketing
The technique of shooting a number of pictures of the same subject and viewpoint at different exposure levels in order to obtain the most accurate result.

B setting
Shutter setting at which the shutter will remain open for as long as the release is kept depressed.

Cable release
Flexible cable used for firing the shutter. Particularly useful for slow shutter speeds and time exposures, when touching the camera may cause shake.

Cassette
Cylindrical metal or plastic film spool container. A light trap allows handling and film threading in the camera in daylight.

Cast
Overall bias toward one colour in a colour photograph.

CC filters
Pale colour conversion filters, used in various hues and degrees of saturation for correcting or inducing colour temperature.

Colour balance
Adjustment in colour photo laureates processes ensuring the accuracy of subject colour rendering under lighting of a particular colour temperature.

Colour Temperature
Convenient way of expressing the colour content of a white light source. Typically, sunlight is 5,400K. Redder household lamps are 2,800K.

Complementary colour
The hue most opposite to a given colour. For blue, green, and red light complementaries are yellow, magenta, and cyan, respectively.

Contact print
Negative-sized photograph made by exposing the printing paper in direct contact with the negative.

Continuos-tone image
Pictures that have a continuos range of graduated tones.

Contrast
The range of tones in a photograph and their graduation. Extremely bright highlights and dark shadows with few intermediate tones give high contrast . Opposite features produce low contrast.

Correction filter
Filter used in front of thr camera lens to correct differences between the colour temperature of the subject lighting and the colour balance of the film.

Cropping
Removing unwanted areas of an image by trimming a print or masking a slide.

Cyan
Blue-green subtractive colour, complementary to red.

Dedicated flash
Flashgun designed for use with a specific camera or group of cameras. It links directly onto the internal camera circuitry, for example reprogramming the shutter, using the TTL meter, receiving ISO data.

Delaying action
Operation of the shutter some time after the release is depressed. Most shutters have a delayed action timer built in.

Density
The darkness of a photo laureates image. A "dense" image is excessively dark. A "thin" image is too pale.

Depth of field
The distance between the nearest and furthest point from the camera within which the subject details record with acceptable sharpness at any one focus and aperture setting.

Development
Key stage in processing, by which the exposed parts of the image become different in appearance to unexposed parts.

Diaphragm
See Aperture

Diffuser
Any substance that can cause light to difuse and scatter.

DIN
Deutsche Industrie Norm. The german system of rating film sensitivity to light.

Diopter
Unit sometimes used to denote the light-bending power of a close-up lens. The diopter value is the number of times its focal length will divide into one meter.

Directional lighting
Illumination that creates a shadowed area one side of the subject and lit surfaces on the other, as seen by the camera.

Direct vision viewfinder
Sighting device with which the subject is viewed directly, without the aid of a prism or mirror.

Distance symbols
Symbols used on the focusing control of some old, simple compacts.

Downrating
Exposing a film at a reduced ISO rating.This is usually followed by held-back processing.

Dry mounting
Method of attaching prints to flat surfaces by heating a shellac layer, under pressure, between the print and the mount.

DX-coding
System using electrical contacts in the camera's film chamber to sense checkerboard pattern printed on film cassette. Automatically sets camera for film speed and length.

Electronic flash
Equipment that produce a brief pulse of light by electrical discharge through a flash tube.

Emulsion
The light-sensitive layers (basically silver halides in gelatin) forming the pale side of the film. After processin, the emulsion carries a permanent, visible image.

Enlargement
Print that is larger than the negative used to produce it.

Enprint
Small enlarged print, with dimensions of a fixed ratio, produced comercially in an automatic printer.

Ever-ready case
Camera case that need not be completely removed to operate the camera controls.

Expiry date
Numbers printed on most film boxes indicating the date before which the material should be processed if it is to maintain its stated speed, contrast, and (if colour) colour balance.

Existing light
See available light.

Exposure
The product of the intensity of light reaching the film (controlled by lens aperture) and the length of time this intensity of light is allowed to act (controlled by shutter speed or flash duration).

Exposure latitude
The amount by which you can under- or overexpose film and still produce an acceptable result.

Exposure meter
Instrument for measuring the amount of light faling on or being reflected by a subject. Generally taken to mean a hand held meter.

Extension tube (or ring)
Metal tube that fits between the lens and the camera body to extend the range of focusing for close-up photography.

Fast film
film which has an emulsion that is very sensitive to light. Such films have high ISO ratings.

Fast lens
Lens with a wide maximum aperture (low f number)

Fill-in light
Light used to illuminate the subject's shadow side.

Film
photo laureates material consisting of a thin, transparent plastic base coated with light sensitive emulsion. After exposure and processing film is left carrying a visible image in black silver or dye.

Film speed
The sensitivity of a film emulsion to light. This is expressed as a speed rating number such as ISO.

Film winder
Term generally used for a simplified motor drive. Gives automatic wind-on after single exposure. Many also allow continuous rate firinf of 2 fps.

Filter
Transparent material, such as glass, acetate, or gelatin, which modifies light passing through it.

Filter factor
Amount by which unfiltered exposure must be multiplied to give the same exposure effect when the filter is used. Taken into account automatically by most meters reading light through the lens.

Fisheye lens
Extreme wide-angle lens uncorrected for linear distortion.

Fixed focus
Camera lens offering no method of focus setting adjustment.

Flare
Scattered light, often due to reflections within the lens, lens hood, or camera interior. Sometimes used to describe glare from illumination reflected from shiny backgrounds. Gives reduced contrast and degraded shadow areas.

Flash
See electronic flash

Flash synchronisation
Arrangement by which the flash fires when the camera shutter is completely open.

Flash lighting
Low contrast. Can also mean frontal, flat-on lighting.

Flash lighting
Low contrast. Can also mean frontal, flat-on lighting.

F number
Number sequences - f2, 2.8, 4, 5.6, 8, etc. - that is equivalent to the focal length divided by the effective diameter of the aperture.

Focal length
Basically the distance between the lens and the film, when focused for a subject at infinity.

Focal plane shutter
Shutter consisting of blinds or blades positioned just in front of the film surface.

Focus
The point at which light rays passing through a lens converge to form a clear and sharply defined image.

Focusing scale
Scale of camera-to-subject distances marked on a lens focusing ring.

Focusing screen
Plastic or glass screen built into SLR cameras at the same distance from the lens as the film. Allows both viewfinding and focusing.

Fogging
Allowing sensitive film to receive generalised non-image-forming light. Has a darkening effect on negatives, gives a pale, washed out result on slides. Can also be caused chemically.

Format
Size or shape of negative, slide, printing paper, or camera viewing area.

Fresnel
Moulded plastic sheet used beneath many focusing screens to improve evenness of illumination. Consists of a series of concentric rings, shaped to direct light toward the viewfinder eyepiece.

Gelatine filters
Filters consisting of thin, dyed gelatin sheet.

Graininess
Irregular clumps of dye molecules or black metallic silver making up the developed image. Graininess limits the image detail recording ability of the film.

Guide number (GN)
Number given by multiplying the flash-to-subject distance by the f number needed to give correct exposure. Often quoted when camparing the light output of different flashguns and, unless otherwise stated, relates to the use of ISO 100 film.

Hard lighting
Harsh contrast. Applies to a photograph with an extreme range of tones or colours, perhaps the result of contrasty light.

Hide
Barrier, hut, or tent used by natural history photographers to conceal themselves.

High key
Photograph in which light or pale tones predominate, rather than dark, deeper tones associated with low-key.

Highlights
The brightest areas of the subject.

Holding back
Shortening the developing time given to a film to help compensate for overexposure, or reduce image contrast. Also known as "pulling".

Hot shoe
Fitting on top of a camera body to hold a flashgun. It contains electrical connections which automatically make contact between flashgun and shutter synchronisation circuit when the shutter release is fired, operating the flash.

Hue
The name of a colour (for example, red, blue, yellow).

Infinity
Focusing setting at which the lens gives a sharp image of very distant objects, such as the far horizon.

Infrared
Band of wavelengths beyond the red end of the spectrum. They are invisible to the human eye, but can be recorded on specially sensitised film.

Inverse square law
The intensity of light reaching a surface is quartered each time the distance from a light sorce is doubled. Does not apply to light sources that are diffused in any way or focused into a beam.

ISO
International Standards Organisation. Current speed system (embracing ASA and DIN) used to express relative light sensitivity of films.

Joule
Standard measurement of the light output of flash units. One Joule is equal to one Watt per second. Most studio flash units specify their maximum output in Joules.

Joiner
A type of montage where a series of shots are taken from the same viewpoint and the prints from those shots are physically stuck together to give an overall vista of the scene.

Key light
The principle of a dominant light source illuminating the subject.

Latitude (of exposure)
The degree of underexposure and overexposure that a photo laureates emulsion will tolerate with acceptable results.

Leaf shutter
Shutter placed within a compound lens, usually close to the iris diaphragm.

Lens
Optical device made of glass or plastic capable of bending light.

Line film
High-contrast film that simplifies the final image to two tones only, black and white, for example.

Long-focus lens
General term for a 35 mm camera lens having a focal length longer than 50 mm. See also Telephoto lens.

Low key
Photograph in which heavy, dark tones predominate, with few highlights. Also applies to lighting that produces such results.

Macro lens
A lens - typically 50 or 100 mm - designed to give best image resolution at close subject distances. The lens barrel allows extended focusing movement.

Macrophotography
Extreme colse-up photography in which images larger than the original subject are recorded without the use of a microscope.

Magenta
Purple-red subtractive colour, complementary to green.

Magnification
Ratio of the height of the image to the height of the subject. When subject and image are the same size amgnification is said to be x1.

Matte
1. Cardboard surround for a picture when framed. 2. Term used to describe a non-reflective, non-textured surface.

Mirror lens
Telephoto lens using mirrors in its construction to allow an extremely long focal length to be accommodated within a short barrel. The aperture is usually fixed. Such lenses are also known as reflex or catadioptric types.

Mode
The programmed operating function of automatic SLR cameras, for example aperture-priority mode or shutter-priority mode.

Monochrome
Single coloured. Most frequently applied to black and white photographs.

Motor drive
Power-driven film wind-on allowing single or continuous firingat a choice of rates, typically up to 5 fps. Usually an accessory attached to the camera base.

Motor drive
Power-driven film wind-on allowing single or continuous firingat a choice of rates, typically up to 5 fps. Usually an accessory attached to the camera base.