[drc]

There are many things that go into a photo but, for news photos, and original by a famous photographer would be at the top. Bain, Conlon et al, often stamped their names on the back.

The quality of the image-- pose, clarity, subject, is also essential value.

Photographers for Hollywood studios and Vogue magazine and the like were often famous, and one of their stamps on back is also very desirable. Movie studios and Vogue had their fancy studios to take photos of famous people. Hollywood studio photos are similar to news/news service photos in that they were used for promotion, often sent to the press, and are stamped on back.