A friend came to dinner Monday night and brought his A7RIV along with him so I could test-mount it on my Actus B. With my camera setup for my C/Y lenses (an FFD of 45.5mm) using a customized Copal 0 lens panel, the A7RIV will just *barely* clear using the standard three-pleat bellows.
Unfortunately, the bellows is compressed as completely as it can be and while it's possible to use the rear rise / fall movement with some effort so long as the A7RIV is oriented horizontally, there is zero ability to apply any tilt and/or swing movements and the shift movement is severely restricted.
With the bellows removed, there was enough clearance that the A7RIV's grip did
not contact the lens panel at its forwardmost extension and actually had a few millimeters to spare in both directions. When I took a closer look, though, I realized the clearance issue isn't with the lens panel, but the steel ring around the opening on the front of the bellows, which has a 4 mm larger diameter than the lens panel, and this is what prevents the bellows from being pushed forward and out of the way by the grip.
Perhaps this won't be a problem with the thinner single-pleat bellows, as least so far as focusing and rise / fall movements are concerned?
Although I do have both of Cambo's Canon EF lens panels (i.e., smart and dumb), I don't have any Canon-mount lenses on hand so didn't bother checking the A7RIV's clearance with either of those. But since the FFD for Canon EF lenses is 44 mm, which 1.5 mm less than the FFD for the C/Y lenses, and the back of the dumb lens panel projects only .35 mm less than the Copal 0 panel (hence only partially compensating for the 1.5 mm difference in FFDs between the Canon and Contax lenses), I believe the clearance issue will be even worse when the A7RIV is used with Canon lenses focused at infinity.
Of course, all of the above also applies when lenses having FFDs even shorter than 44 mm are used, which includes most wide-angle view camera lenses.
