Berthiot Pan-Cinor 17.5-70 Focus Aid Problem

Garrett Anderson · June 2

Summing it up- new used lens everything is perfect except I cannot use the focus assist. The frame mask was at an off angle The split circle moved with this mask, but it must have been off anyways because when i looked through it the focus assist was black even at wide open aperture.

To start this off I have a 17-85 pan cinor as well. I had a problem where the mask inside the viewfinder was rotated 30 degrees off. I rotated it with a micro flathead screwdriver and then the focus assist behind the mask unintentionally rotated with it a black circle.

It did not help that he dogleg viewfinder has a completely cracked lens inside it but I was able to after scratching the mask excessively, rotate it around so the mask was on straight and the focus aid prism seemed to work.

I went ahead and ordered another pan cinor lens on ebay, because the 17-85 I had came janky with a broken lens in the viewfinder. I got a Pan-Cinor 17.5-70mm listed in EX+++ condition whatever that means... everything is clear through the lens, no fungus, everything works correctly, except when I looked through the viewfinder, the focus aid circle is black so I cannot use it to focus my image at all Also the mask was at an off angle so my framing would not be straight on. I loosened the innermost screw which moved everything and adjusted the mask and SAME THING the prism moved with it.

On this lens no matter what angle i adjust the focus assist to, it remains black. plus the only way to rotate it around is to push a small flathead into the corner and spin it.

Yes I do not know what I am doing, it seems the only damage I am really doing is scraping the black coating off he metal frame mask, but I cannot for the life of me figure out how the focus assist circle is supposed to be oriented properly.

There are no service manuals for these lenses anywhere online and I cannot find any mention of this except a thread from 2008 on these forums where someone talked about rotating the mask to straighten the frame through the viewfinder. It did not mention the fact the split image focus assist rotated with it!!!

I horrible that ive scratched these lens masks, but the fact is the lens i bought has a black focus assist prism. There is nobody in Austin Texas or the state I have found that knows anything about these. I am just trying to DIY this and hope that I can get this otherwise pristine lens to work.

Edited June 2 by Garrett Anderson