Characteristics of Collodion and protein Printing

Collodion and protein printing have different characteristics.

Colloidal collodion is a colloidal emulsion produced by dissolving collodion (nitrocellulose) in alcohol (ethanol) and ether. It has a good adhesion to photosensitive materials. When in use, collodion is coated on a clean glass plate and put into silver nitrate solution, and silver nitrate reacts with silver iodide and potassium bromide on the glass plate to generate silver iodide and silver bromide crystals with photosensitive effect. This glass-based "collodion" photosensitive material can be photographed immediately. Its advantage is that the picture quality is very clear, but it is dangerous to use because it is easy to burn.

Protein printing is an ancient photographic technology, which takes protein paper as photosensitive material and combines with the wet printing process of collodion. The picture quality of this method is also very clear, and in the landscape photos taken, the sky is mostly white, the background is dark, and there is no hierarchical change. However, the shooting of protein printing needs certain skills and experience, such as accurately controlling the exposure time and development process, otherwise it is easy to have problems such as blurred images and color distortion.

Generally speaking, collodion and protein printing are different in image quality, operation difficulty and applicable scenes. Choosing which technology to use needs to be decided according to the specific needs and shooting scenes.