COKIN "A" SERIES A004 GREEN FILTER - BLACK & WHITE CONTRAST CONTROL - NOS

This is a new old stock Cokin A Series Green A004 filter. The A004 is primarily used in black & white photography to alter contrast between objects of similar reflectance. It functions in the film or digital domains. In color it will produce a pronounced green color effect.

Cokin filters require the use of a Cokin filter holder and an adapter ring to attach it to your lens. A single A filter can fit  lenses from up to 62mm using the proper adapter ring.

Black and white imaging records only tonal differences between colored objects, which appear as black, white, or different shades of gray.  Proper rendition depends on your own desires, and, for film, the differences between film sensitivity to colors and that of the eye.  The latter is due to the fact that most panchromatic emulsions used are more sensitive to blue, violet and ultraviolet than to other colors. A green filter can be used to lighten green foliage, showing more detail.  It may also be used to provide more pleasing skin tones outdoors, especially against blue sky. It’s function depends on absorbing light of its complementary colors thus causing elements of the photo reflecting that spectral range to appear darker. This increases the apparent exposure of colors similar to itself making those areas of the photo lighter.  Exposure compensation is often needed to allow proper exposure. A little experimentation will allow the user to obtain the exposure desired.

Using filters for contrast control can be a matter of artistic preference, or of necessity.  It is possible for two disparate colors, say a certain orange and blue, to record as the identical tone, eliminating any visible difference between them.  Filters will lighten objects of their own color and darken those of their complement.  Complementary color pairs are: green-red; orange-blue; violet-yellow.  An orange filter in the above case will darken the blue, and lighten the orange; a blue filter will perform the reverse.