Contrast, Photographic

Contrast, Photographic

 

a characteristic of a blackand-white photographic image according to the ratio of the brightness properties of its lightest and darkest areas. The following two methods are most widely used for determining photographic contrast: (1) by means of the transmission factors τ (for images on film) or reflection factors p (for images on photographic paper):

or

respectively; (2) as the optical density difference Dmax — Dmin (known as the photographic image density interval).

The greater the contrast of the object being photographed and the greater the gamma of the photographic material (if the conditions of photography are correctly chosen), the greater the photographic contrast.