Polaroid 405 holder compatibility with Sinar F2

[rdenney]

Any problems with the method of putting the film holders in front of the ground glass?

For holders that don't have protrusions that will bear on the glass directly, and if the spring arrangement of the ground-glass holder has sufficient travel to accommodate the thickness of the back, then there's nothing wrong with just sliding it under the ground glass. I do not know whether the back on the Sinar will accommodate a Polaroid 405, aside from the issue described by the OP. It will absolutely accommodate a Fuji PA-45 in that way, though not with an abundance of margin. I just tested it. The PA-45 back is about 1.07" thick.

Rick "noting that the bail tab has a 1" travel, so lifting the back itself is required with the PA-45" Denney