TECHNICAL TERMS - A
APERTURE
  • The size of opening set by the camera to control the amount of light reaching the film through the lens.
  • Used in conjunction with the shutter speed to give an accurate exposure.
​APERTURE PRIORITY
  • Semi-automatic exposure system whereby the photographer sets the aperture and the camera selects the corresponding shutter speed to ensure the correct exposure for the scene.
​ARTIFICIAL LIGHT
  • Any light other than daylight.  This can include flash or ordinary household lights.
​ASA
  • American Standards Association.  This is a means of measuring a film's sensitivity to light.  Same as DIN and ISO.  The higher the ASA speed, the more sensitive or faster the film.
​AUTOFOCUS
  • A system where the camera measures the distance to the subject and focuses the lens accordingly.
​AUTOWINDER
  • Automatic mechanism that advances the film one frame each time the shutter is released.
​AVAILABLE LIGHT
  • The existing light available to take the picture without using a flash.  This could mean daylight, floodlight or domestic light.