I'm trying to improve my knowledge on the finer points of lens mounts, and I have a couple of questions regarding FFD and how it applies specifically to PL mount lenses.
First, I'll mention that I do understand the concept of FFD as the distance between the lens mounting flange on the camera and the film plane. I also understand that the FFD varies from one lens mount to another, and that the FFD for PL mount is 52mm.
Here's where I'm curious. I've looked at a number of different PL mount lenses, both prime and zoom lenses, and it appears as though there's some variation on the distance between the mount on the lens and the rear element on the lens. My initial question is this...what's the technical term for the distance between the mount on the lens and the rear element on the lens? And, if my observations are correct and this distance can vary from one lens to another, then this means that the distance between the rear element of the lens and the film plane can also vary depending on which lens is used. That said, I'm curious how this doesn't result in a myriad of focusing issues. I'd think that for proper operation, not only would the FFD need to be consistent, but also the distance from the mount on the lens to the rear element of the lens and, consequently, the distance from the rear element of the lens to the film plane.
Along the same lines, if these variations do exist, then do manufacturers specify a maximum/minimum value for their cameras? For example, I could see a situation where the rear element of a PL mount lens might have plenty of clearance on a digital cine camera, yet it might be too deep for a 16mm Arri or Aaton and could potentially interfere with or crush the rotating shutter.
Thanks in advance to anyone who can help with my questions!