Grey-scale test slide

Claim 1

A test film frame for incorporation in a slide, motion picture or the like, for use in the testing and alignment of colour cameras employed in colour television such as colour telecine camera chains so as to bring said cameras into alignment with predetermined desired standard characteristics at different densities of red, green and blue in images sensed by such colour camera chains thereby to produce accurate reproduction of colours in such images when displayed on television and seen by the human eye in which errors in light transmission of light of different wavelengths due to presence of light scattering substances in the film material have been eliminated, said frame comprising; a portion of exposed and developed dye image type colour film from which substantially all light scattering materials have been removed; a plurality of distinct strips of separately exposed dye image materials within a central area of said film portion one of said strips being of a grey density paler than the others, another of said strips being of a grey density darker than the others, and the remaining said strips being arranged in varying intermediate densities of grey, said strips being arranged in a row with the paler said strip at one end and the darker said strips at the other end, and the intervening said strips being arranged therebetween in graduated order of density, each of said strips comprising evenly exposed and developed dye image materials from which substantially all light scattering materials have been removed within said portion of colour film, said dye image materials providing predetermined specified densities with regard to red, green and blue light respectively, and together providing a combined predetermined specified grey density, said specified densities being matcHed to the desired standard characteristics for colour telecine camera chains as aforesaid; and a neutral border surrounding said strips of substantially even density through out its extent.