Correct exposure is the essence of good photography.
The Kodak Gray Card is a consistent neutral test target that allows you to eliminate variables in your determination of proper exposure.
Both in camera and handheld exposure meters provide exposure information for an ''average'' scene, one that contains a balance of dark and light tones equal to middle gray.
Exposure errors occur when a meter reading is taken off of a subject that is lighter or darker than middle gray.
By taking reflected-light meter readings off of a Kodak Gray Card rather than a subject of unknown reflectance, more accurate exposures will result.
