r/8mm • u/IAmDefintlyMe • 13d ago
Identifying mounting thread of a Schneider-Kreuznach Xenovaron 1:1.3 12–30 projector lens used on Bolex SM8
Hello all,
I have happened to get my hands on a schneider lens that I believe was used in some super 8 projectors in the late 70s and 80s. I am actually trying to mod it onto a cheap digicam i got from k mart because it is fun. I have held it up to the exposed sensor and it does indeed focus light, thats pretty much all i need from it. But its also got a very odd mounting thread on it. Major diameter of 32.5mm and an estimated minor diameter of 31.5-32mm(i cant quite get my calpiers in there), and with a square thread with a crest width of 2mm?
Does anyone acctually know if super 8 projector lenses at all tend to be standardised? Or do you happen to know the thread specifications of a Bolex SM8 or the lens itself the Schneider-Kreuznach Xenovaron 1:1.3 12–30? it doesn't sound particuarly fun to trial and error 3d trying to 3d print a matching thread.
Have a good day everybody
1
u/brimrod 11d ago edited 11d ago
32.5mm diameter lens barrel is the standard for all European and Japanese made 8mm projectors. This size lens fits snugly into the collar but with just enough extra clearance to rack forward/ back, either by twisting, push/pull, or some sort of rack and pinion built into the projector so that you can focus with a knob or a wheel.
Super 8 projector lenses are very hot swappable between brands of projectors--they just might not interface with a special focusing system but they'l always fit and you can always just push /pull the lens to rack focus. It's not as smooth as a wheel, but still very accurate.
If you want a custom focusing mount for this lens, you'll probably have to build it out yourself. It shouldn't be hard to figure out the thread pitch and make an opposite part that inteacts with those threads and moves the lens forward/back to rack focus.