Old photographs are not just pictures showing some image, but, their anatomy, composition, texture and information written/printed/stamped etc. tell a lot more about the time, people, techniques of photography, its stability/instability with time and how it can be preserved or treated.
These days , at Heritage Preservation Atelier, we are working on a collection of photographs. An objective view of a photograph gives a lot of information about its time period, what is shown in the picture and what is its significance.
A brief information about how old photographs are studied and analyzed is explained in the following chart:
Some information written/printed/stamped on the photograph is visible to naked eye, but at times, we also find written information when we are observing the surface under UV light or through a magnifier.