@Paul Howell - Cool! Thanks for the comment! Yeah, the camera makes a pretty loud clap like a medium-format camera, but I still like shooting it. By the way, I have a question that you could maybe help me with. Would a W-Komura Uni Auto 35mm f/2.5 be able to be used safely on the Topcon Unirex? I've read that Hi Topcor lenses may/may not be used on the Unirex, but a little unsure about Uni Auto lenses. What do you think?
the Unirex is similar to the Topcon Auto 100...small diameter lens throat with leaf shutter in the body immediately behind the lens mount (listed specs are from Unirex information)
- Lens mount: UV Topcon bayonet mount. The mount included a locking facility when Topcor UV lenses are attached.
- Viewfinder: Fresnel screen with central mirco-prism focusing spot, and a fine focusing ring around this. Magnification x 0.75.
- Shutter: Seikosha SVL leaf shutter in camera body. Speeds 1 sec to 1/500th plus B and self-timer. 1/15th to 1/500th available for auto-exposure (in red: lower speeds in black). 10 sec self-timer (set MVX switch to V, and press shutter release).
Highly unlikely you can use the Komura, unless you can get seller to measure the diameter where the yellow arrow is in this photo, and it measures <21mm.
From what I can tell, the Komura UNI was a multi-mount lens, similar in concept to the Tamron Adaptall 2 lenses, and while Komura did have a 'Topcon' mount, it was actually for the RE (Exacta) mount lenses for the higher end (than the Auto 100/Unirex) SLR bodies.
The back of the above lens does NOT appear to be compatible with the Unirex mount. The Hi Topcor lens DOES appear to be compatible. I would have to research more to learn why the Hi Topcor lens would not be compatible.
By my understanding, after doing some research, there was some mount change basically due to the removal of the behind-the-lens leaf-shutter, all lenses made for focal plane shutter IC-1 have the HI Topcor marking. Four HI lenses made for IC-1, two 50mm versions (f/2 and f/2.8), one 55mm (f/1.8) and one zoom 87-205mm f/4.7. The HI Topcor indicates that these lenses are for the IC-1.