Photography terms starting with A

Abstract Photography Genres, Movements & Theory Photography that emphasises form, colour, texture and pattern over the identification of its subject.

Action Camera Cameras, Formats & Systems A small, ruggedised, wide-angle camera built to be mounted on a body, vehicle or piece of equipment.

Acutance Optics, Lenses & Filters The abruptness of the transition at an edge, which the eye reads as sharpness independently of true resolution.

Added Grain Post-Processing & Retouching % Synthetic texture introduced into a digital image to imitate film grain or to disguise other artefacts.

Adjustment Layer Post-Processing & Retouching A layer containing a tonal or colour adjustment that affects the layers beneath it without altering their pixels.

Adobe RGB (1998) Colour & Colour Management A colour space with a wider gamut than sRGB, particularly in the cyan and green regions, designed to cover CMYK print output.

Advertising Photography Genres, Movements & Theory Photography commissioned to promote a product, service or brand.

Aerial Perspective Composition & Visual Design The reduction of contrast, saturation and detail with distance, caused by atmospheric scattering.

Aerial Photography Genres, Movements & Theory m (altitude) Photography made from an elevated platform — aircraft, helicopter, drone or kite — looking down on the subject.

AF Microadjustment Focus & Depth of Field steps (typically ±20) A camera setting that applies a per-lens correction to compensate for consistent front or back focus.

AF-assist Illuminator Focus & Depth of Field A lamp or patterned light that projects onto the subject to give autofocus something to measure in darkness.

Agitation Film, Darkroom & Historic Processes seconds per interval The periodic movement of the developing tank that replenishes fresh chemistry at the emulsion surface.

AI Denoise Post-Processing & Retouching % Noise reduction driven by a trained neural network that distinguishes noise from real detail using learned image structure.

AI Subject Selection Post-Processing & Retouching Automatic masking that identifies a subject, sky, background or facial feature using a trained model.

Airy Disc Optics, Lenses & Filters µm The small bright disc surrounded by faint rings that a perfect lens produces from a point source, set by diffraction alone. d = 2.44 × λ × N

Albumen Print Film, Darkroom & Historic Processes A printing process using egg white to bind light-sensitive silver salts to paper, giving a glossy surface and warm brown tones.

Aliasing Sensors & Digital Capture The misrepresentation of detail finer than a sampling system can resolve, appearing as false structure rather than as blur.

Alpha-cellulose Paper Printing, Display & Output g/m² Paper made from highly purified wood pulp with lignin removed, offering archival stability at lower cost than cotton.

Amp Glow Sensors & Digital Capture A coloured brightening at one edge or corner of a long exposure, caused by heat and stray light from on-chip electronics.

Analogous Colours Colour & Colour Management Colours that sit adjacent to one another on the colour wheel, producing a harmonious and unified effect.

Analogue Gain Sensors & Digital Capture dB or × Amplification applied to the sensor's signal before it is digitised, which is the physical mechanism behind ISO settings.

Analogue-to-digital Converter Sensors & Digital Capture bits The circuit that turns the analogue voltage from each photosite into a discrete numerical value.

Anamorphic Lens Optics, Lenses & Filters squeeze ratio (e.g. 1.33×, 2×) A lens containing cylindrical elements that squeeze a wide field horizontally onto a standard frame, to be unsqueezed on projection. Desqueeze = width × squeeze factor

Angle of View Optics, Lenses & Filters degrees The angular extent of the scene a lens and sensor combination captures, usually quoted across the frame's diagonal. θ = 2 × arctan(d / 2f)

Terms starting with A