ABSTRACT
Films or digital image chips need to receive just the right amount of light to record an image. If
insufficient light reaches them they record nothing, or a dark, partial picture. Similarly, too much
exposure results in a bleached, washed-out image or just a white blank. Strictly speaking, ‘giving
the right exposure’ means capturing the correct amount of image light (photons). In practice it is
much more than this. Exposure can be used to give emphasis, by deliberately over-or under-
exposing parts of the scene such as backgrounds to draw the eye towards the main subject.
