I've taken the lens elements out of the Bronica lens housing and fitted them onto a compur rapid shutter, which is positioned to use hyperfocal distance rather than manual focussing. Now of course, I have to recalculate the aperture widths and re-mark the shutter, which I did using 40mm in the calculation. Since I've ended up with underexposed frames, I'm guessing that I should have used the measured 76.5mm flange plate to focal plane distance, but I can't find any information to support this assumption.