A
- A-mount (Sony)
- AA batteries
- Aberrations
- Accessory shoe
- ACROS (Fujifilm)
- Action cams
- Active D-Lighting
- Adjustment layer
- Adobe Camera RawSoftware tool that works alongside Photoshop to open and process RAW files.
- Adobe ProPhoto RGB
- Adobe RGB
- AE-L/AF-L button
- AF (autofocus) points
- AF-P lenses (Nikon)
- AF-S lenses (Nikon)
- AF AssistSmall but intense lamp on the front of a camera to aid autofocus in low light.
- AF coverage
- AF fine tuneIn-camera adjustment to correct for any slight autofocus errors with DSLRs and their lenses.
- AF mode
- Alkaline batteries
- Alpha (Sony)Brand name used by Sony for its interchangeable lens cameras.
- Aluminium (tripods)
- AnalogA term to describe old film cameras, films, development and darkroom processes.
- Angle of view
- Anti aliasing filter
- Aperture (lens)
- Aperture blades
- Aperture priority (A) mode
- Apochromatic (APO) lensA lens design that counteracts chromatic aberration.
- APS-C sensor
- APS-H sensor
- Arca Swiss
- Area/auto AF
- Artefacts (digital)
- Aspect ratio
- Aspherical lensA lens element with a complex (non-spherical) curvature.
- Astia (Fujifilm)
- Auto exposureWhere the camera measures the light and sets the shutter speed and/or lens aperture on its own.
- Autofocus
- Autofocus speed
- Auto ISO
- Auto mode
- Auto white balance
- AVCHDVideo format once used extensively by Sony and Panasonic but less common now.
- Average metering
- Axial chromatic aberration