Phenomena essential for practical photography were investigated by means of electron microscopy with the emphasis on the transformation of the size of colloidal silver particles and change of their spectral properties. Ways to change this size during photographic processing of the layers were studied and their mechanisms were worked out in detail in order to optimize them. It was established that in the process of spectrozonal intensification massive image silver with particle size of 0.1 to 0.2 μm was transformed into colloidal particles with the size of 3 to 6 nm. This process was accompanied by increase of spectral absorption intensity with its peak at 450 nm. Roles of formation of soluble silver complexes, influence of halogen ion, and multicyclicity of the process were investigated. Study of oxidizing dispersion properties of silver in a chromium halide bleacher with successive intensification of the silver image showed that effective dispersion of silver halide microcrystals could be achieved for the case of oxidation in chromium(6+) chloride or chromium(6+) bromide bleachs with high hromium(6+): chloride (bromide) molar ratio, as well as in the case of strong repeated reduction in the stannous chloride or borohydride salt solutions. It was noted that the chromium compounds played only a small part in the processes connected with silver particle transformation, and the intensification ratio depended on factors influencing morphology of silver halides (formed in the process of bleaching of initial colloidal silver particles) as well as the morphology of secondary silver obtained after redeposition of AgCl.