Hi All, Im a novice to Large format photography. I work on cinema lenses, and have used most currently available formats. I have been thinking on getting into 4x5 Large format photography and the one thing that i can't seem to find info on is if there is a way to identify what format the camera is designed for. A Lot of my window shopping has been on Ebay and it seems like some of the cameras are mislabeled. Is there any way to identify them, or am i looking at these the wrong way.

Thanks,

Hmm. This is a slightly hard question.

I don't know what you mean by "back," have to assume that you mean film holder. If the photos in a listing show the back of the camera, its aspect ratio will tell you. 2x3 (6x9 in metric) is relatively longer and lower than 4x5, and so on.

If you want to get many replies, try asking on https://www.largeformatphotography.info/forum/

Beware...
On Ebay, sometimes 3x4 Speed/Crown Graphics are mistakenly advertised as 4x5...they can look similar in photos.
If in doubt, ask the seller to measure the ground glass.
It is also important to understand the differences between
"Graphic" , "Graflex" and "Graflok" backs...
That information has been provided here numerous times, so a little bit of 'digging' will be worthwhile.