Specific steps of silver plate photography

① Prepare a copper plate plated with thin silver;

(2) cleaning and polishing;

(3) putting into a small box filled with iodine solution or iodine crystal, and reacting iodine vapor with silver to generate silver iodide. The time is 30 minutes.

(4) transfer to a cassette;

⑤ Put the tapes together in a black box for shooting, and the time is 15 ~ 30 minutes. Under the action of light, silver iodide is reduced to metallic silver with different densities according to the intensity of light, forming a "latent image".

⑥ It was put into concentrated hot salt solution and was "fixed" under the action of sodium chloride.

⑦ Wash and dry. Exposing the silver disk to iodine or bromine vapor will produce a uniform photosensitive surface of silver halide. Exposure time will decompose silver halide, leaving pure silver, and the silver halide in the dark area is still intact. The silver plate is exposed to mercury vapor, and mercury combines with pure silver to form silver-mercury crystals. (This process adsorbs silver to the surface, resulting in the formation of cavities under the surface, which leads to subsequent damage under illumination) Wash the silver disk in sodium thiosulfate (fixative) solution to remove the residual silver halide. In this way, some pure silver surfaces look black, while some amalgam crystal surfaces will refract light into white.