Abstract: The imaging process with multi-stage amplification by copper physical development was studied with different emulsion coatings: the positive cine film, the negative emulsion coating, the direct positive emulsion coating and radiographic film. The results. showed that the sensitivity of the emulsion layer can be increased significantly by the copper physical development and the amount of coated silver can be greatly reduced. It is extremely interesting, as shown in this work, that a Lith Effect can easily be obtained by the copper physical development. The imaging process with multi-stage amplification can find practical applications in the following cases: i. the enhancement of faint images otherwise would not be detected; ii. the development of photographic materials with extremely low silver content; iii. the reduction of X-ray dosage in medical rediography.

Key words: imaging process, physical development image amplification, photographic characteristics