of or relating to an emulsion giving a rendering of relative light intensities of different colours that corresponds approximately to the colour sensitivity of the eye, esp one that is insensitive to red light
Sometimes shortened to: ortho. Compare panchromatic
Derived forms
orthochromatism (ˌɔːθəʊˈkrəʊməˌtɪzəm)
noun
orthochromatic in American English
(ˌɔrθoʊkroʊˈmætɪk)
adjective
designating or of photographic film that is sensitive to all colors except red and deep orange