A distortion of image quality or color rendition in a photographic image caused by optical limitations of the lens used for image […]


A term applied to a lens that has been corrected for chromatic aberration so that it brings light rays of two colours […]


ADC Analogue-Digital Converter. Hardware that converts analogue information into digital data.

Additive colour mixing

Describes a colour system that is based upon the addition of the three additive primary colours (red, green and blue). For example, colour televisions and computer monitor displays use the principle of additive colour mixing.

Adobe RGB

A widely accepted color space that encompasses a wider range of color than the more commonly used sRGB color space. Adobe RGB […]

AF Metering Field

Spot or area in the frame marking the position where the autofocus system takes readings to set the focus.


Opposite of digital. Analogue data merges continuously into each other without clearly defined steps. (E.g. the colours of a rainbow are not obviously separable […]


An anastigmat lens is one in which all optical defects, including astigmatism, have been corrected in the design. The first of this […]


The aperture is basically a hole in the camera’s lens that lets light pass through it to the shutter and ultimately the […]

Aperture Priority

In this mode, the user can adjust the aperture and the camera automatically selects the best shutter speed to match it. In most cameras, the Aperture Priority mode is usually denoted by the letter ‘A’. Most film SLRs were made as Aperture Priority – e.g. Nikon and Olympus.


Advanced Photo System film is a discontinued film format first made in 1996. Kodak sold APS film under the brand name Advantix, […]

Aspect Ratio

The aspect ratio is the relationship between an image’s height and width. Aspect ratios are more often written with the width first, […]


Autofocus (AF) is an optical system that uses a sensor, a control system and a motor to focus on an automatically or […]

Back Button Focus

Back button focus is a technique used in photography that separates the focusing and shutter release functions on a digital camera. Instead […]


A bloomed lens is one that has had one or more of its air/glass surfaces coated with a thin film of metallic […]


An English transliteration of a Japanese word that means “haze” or “blur.” Pronounced boh-keh, it refers to the out-of-focus areas in a photograph with […]


Bulb mode/setting (B) is a shutter speed option that you can select. It allows your shutter speed to be any length you […]


A CCD (Charge-Coupled Device) is an integrated circuit containing an array of linked or coupled capacitors and it is one of two […]


The term ‘Clean, Lubricate, Adjust’ (CLA’d) is used mostly for cameras but also for lenses. It is often abbreviated to CLA or […]


A CMOS (Complementary Metal–Oxide–Semiconductor) is a type of metal–oxide–semiconductor that is one of two types of sensors used in digital cameras, the other being […]