EXPERIMENTAL INVESTIGATIONS OF THE NOISE TRANSFER FROM SILVER-HALIDE NEGATIVE FILMS TO PRINT MATERIALS

According to the linear information theory the noise transfer from a n egative master film to a copy material can be described in terms of th eir three basic characteristics: characteristic curves, noise power sp ectra and modulation transfer functions. This concept was tested exper imentally for a variety of negative films and transmission and reflect ion copy materials. The verification experiments covered a wide range of possible negative/positive combinations starting from the simplest case of a contact copy from one black-and-white film to another. In th e final experiment the practically most relevant case was studied by e nlarging a medium-speed colour negative master onto photographic colou r paper at different magnifications. The linear information theory pro vided an accurate explanation of all experimental results except at hi gh magnifications.