Glossary

The base for APS film emulsions. Its a strong material that it accepts film emulsions evenly and, with a thickness of just 90 microns its 30% thinner than the acetate base used in conventional 35mm emulsions.

A device found in digital cameras and scanners that converts analogue picture information (continuous tone subject) to digital data (digital image).

Optical problem in a camera lens that produces slight errors in subject appearance, usually noticeable in small details.

Image which does not depict something in a literal nor complete way. For example, a close-up which removes the original's form and function, else an image with the original so obscured as to make other interpretations very apt.

A chemical ingredient of film or paper developers that's often referred to as an activator and speeds up the developing agents. It's usally an alkali such as sodium carbonate, borax or sodium hydroxide.

A chemical substance such as a stop bath or fixer with a pH below 7 that's used to stop film or paper development.

A camera with active autofocusing uses an infrared beam to determine how far away the subject is. This is fine providing the subject isn't behind glass, because the beam will think the glass is the subject. The system is also flawed when the subject is beyond the range of the infrared, then the camera usually switches to an infinity mode.

A measure of how the step from high to low density reproduces in a developed film that has been exposed to a high contrast subject. A high acutance developer produces a steeper step from low to high density and, as a result, makes the image appear sharper

A camera lens accessory that fits onto the filter thread of a lens to allow a filter system holder to be attached. Other types are available that step-up or step-down from the actual lens filter diameter to allow other size filters to be used.

Process that exposes different amounts of red, green and blue primary coloured light onto colour printing paper to create a new colour.

A new film format developed and introduced by Minolta, Nikon, Fuji, Kodak and Canon back in 1996.The system was developed to make it easier to load into cameras and offers many processing benefits. For more information, see "APS"

Where the camera measures the amount of light required for a scene and adjusts the exposure to suit.

A button or lever on the camera or exposure meter used to lock the automatically measured light reading into a memory while you recompose.This is ideal for backlit subjects because you can move closer to the subject, take a reading without any background in the view, lock the exposure and move back to the original position to take the photo.It's also fine for landscapes when there's an expanse of bright sky. Point the camera down to the ground, lock the exposure, recompose and shoot.Use this to bias the exposure to one area of the scene or to maintain a consistent reading when lighting conditions are variable.

An infrared or bright light beam that fires from the camera to the subject to determine camera to subject distance or to assist autofocusing in low light.

A mode to lock the focus to a predetermined point. Useful when the subject is moving fast because you can take the photo as it reaches a certain point or when other influences could affect the focusing such as shooting through glass or in crowded locations.

Digital images are made up of square pixels and when the image is low resolution there are fewer pixels per inch. This creates a rough step-like appearance that is most noticeable on diagonal straight edges. This staircase effect is often described as "jagged".

Available light - this can be any kind of light that's already there, such as daylight or artificial light - as opposed to light the photographer adds with a flash gun or other photographic lighting unit.

A measurement of ambient light.

The range, usually indicated as a range of EVs (exposure values), that the meter can work in. The larger the range the more versatile the meter. An ISO film speed is usually quoted to indicate what the measurement scale is based on.

Responsible for supplying the speed rating of photographic film. Doubling the ASA number indicates twice the light sensitivity. ASA was replaced with ISO in the 1980s.

Used to describe the stereo photography method of viewing images using deep red and green spectacles. The two pictures have their red and green content displaced which gives the three-dimensional appearance when viewed through the special eyepieces.

An optical design that gives different image magnification in the horizontal and vertical planes creating a widescreen image.

The amount of a distant scene that can be viewed using a camera lens. This varies with the focal length of the lens and film format.

A figure generated to indicate the light sensitivity of printing paper. Not to be confused with the ANSI computer character standard.

A method of smoothing out pixels' jagged edges using software.