Software for dating photos
Another clue might be the background, and on many the photographers name will be on the bottom of the cabinet card or on the back of the picture.
Daguerreotype photographs were 8 ½ inches by 6 inches, and the first of these were used in 1839.
And mostly, the problem with the pictures we capture is that they are blurred.
Ozotope was another method that was used beginning in 1898, this was a process that used gelatin silver bromide, which transferred by contact with pigment paper.
The one thing that was odd about these photographs, was that the picture would appear opposite of how the person was standing or sitting, just as they would appear in a mirror.
The material that was used for these photographs was not actually tin, but became referred to as tin because they were made out of cheaper metal, rather than silver.
The process for these pictures was done by using a plate, made of copper and using silver iodide to expose the picture, along with exposure to light.
Tin type pictures were introduced in 1853, and became extremely popular.
There are pictures that used daguerreotype, glass plate, cabinet card, and the thickness of the cabinet card can also tell the age of the picture.