Dating photographs is not always an exact science, but a surprising degree of accuracy can often be achieved, and this frequently results from assessing evidence of several different kinds. It is, therefore, worth taking the time to compare all the dating clues that can be gleaned from an old portrait.
Pointers can be found in the type of photograph, the identity of the photographer, and the case or mount with which the picture has been provided. Then there is the image itself, which can provide telling information in the studio background and props., in the composition and technique, and in the clothes worn by the sitter. With some types of clues, the possible time span may be broad, but dating conclusions are often reached via an accumulation of approximations. The greater number of clues we can recognize,, therefore, the more confidently we can draw conclusions about a possible date range.