Wratten Filter, numbers 61, 29 and 47. 7x7cm each filter and 22x22cm the frame.

The gelatin optical filters are used for color separation work in photography. The filters complement each other absorbing a 100% the red, blue and green wavelength colors from white light. When ordered together one in front of the other, the result is a complete absence of light, no surface reflection but an optical effect of deep black out of light.