Did anyone mod the Optivaron 1.8/6-66mm for the Bolex H8 RX?

[Ruotsalainen Werner]

I’ve just received my third Double Super 8-modified Bolex H8 RX camera. This time, it came with a lens with the title “Optivaron 1.8/6-66mm für Leitz Leicina”. That is, it was originally M-mount and not C-mount. (I assume C-mount lenses wouldn’t have any reference to Leicinas?) Not that this would matter much as the originally C-mount (shipped with for example the Beaulieu 5008 S) lens wouldn’t be compatible with the Bolex H8 RX cameras either.

Interestingly, the lens is compatible with the RX system. I’ve tested different focussing distances and haven’t encountered problems. That is, whoever (mechanically) changed the original non-RX-compatible lens to become compatible with the Bolex system did a good job. (Note that I still haven’t shot with the new lens. Will do it as soon as my new package of Foma R100 films arrive here.)

I couldn’t find any info on whether anyone has modified these lenses to have the flange distance required by the RX cameras on any forum.

Note: I’ve also tested the lens on my Beaulieu 5008 s, which also has a standad C-mount. As expected, a subject at 3m was the sharpest at inf (but not fully sharp!). And, of course, standard C-mount lenses like the Angenieux 6–80 mm f/1.2-1.4 (which originally came with my 5008s) are the sharpest at the closest distance (way below 1m?) because of the incompatibility.

Here’s a photo album (shot with the Sigma DP2M for the best possible quality) with the lens (and three other 8mm zooms). The (again, RX-compatible) 6-66 is the one on the far left. To the right, the native Super8 6-80 follows; then, the single (native Regular 8 ) RX zoom (the 8-36) I had previously known of and, finally, the native Super8 8-64. The 6-80 and the 8-64 are standard C-mount ones (flange focus distance = 17.52mm). (Incidentally, I’ve shot a full series of test images with these two zooms with my Fuji X-E1 and Pentax Q7, see my previous postings on this.) I couldn’t discern any clear signs of a manual mod on the 6-66.

By the way, with the non-Reflex Bolex H8 mod (D-mount), I now have four DS8 Bolex H8 mods. Here are some photos of these cameras. And my YouTube channel is full of (currently, Finland-only) shots with these cameras. A shameless plug - look for anything with the prefix “[D]S8” or “8mm scan” and any reference to the Bolex in either the title or the description.

Edited January 26, 2020 by Ruotsalainen Werner
typos, grammar

[Jean-Louis Seguin]

You can use any regular C-mount zoom with the H8RX if you have a custom made turret which has one of the openings 2.213mm thicker. You might still get a little loss of quality at fully wide open aperture but at least you can focus the lens properly.

[Andries Molenaar]

Indeed curious. Obviously the M-model needs far more back-focus-distance than the C. Apparently Schneider had various set-ups for several destinations. The M might possibly fit some digital still camera's too ?

Finding an adapter to put it on D-mount or others with short distances to flange shouldn't too difficult. There so many adapters these days.

Mind that the retro-lens on the rear doesn't move for focussing. That is all done in the front part.

Edited January 30, 2020 by Andries Molenaar