Leica LTM Weird Difference in Leica IIIC & IIIF viewfinders

[Steve Karr]

Hi everyone,
I just got 2 III's. A IIIC & F. The F is in SUPER clean shape and the C is nice / average.

My question is when I checked the viewfinder on the F for calibration I noticed the "Patch" was MUCH more dim in comparison to the patch in the C.

The thru part of the viewer is the same (the F had a red filter in place of the clear) but the patch is at least 2 (maybe 3) stops darker. This can't be right, it's not useable inside or in dim light this way. I would love to clean, adjust, etc the F to bring it to useable state. The C is really bright in comparison.

So what do you guys think?

Thanks~
Steve

ps. that is the counter selector collar around the shutter speeds for?
I'm such the NUBB.

 

[sanmich]

For some reasons, the beamsplitters on IIIf are more prone to deterioration than others.
I had two, and both needed a replacement.

 

[colyn]

The beamsplitter mirror needs to be replaced. This is a semi-transparent mirror usually 40/50% or 50/50%. It allows about half the light through to the viewfinder and reflects the rest to the movable mirror.

 

[colyn]

ps. that is the counter selector collar around the shutter speeds for?
I'm such the NUBB.

That is the flash sync dial which is used to select the proper setting for the type of flash used.

If the numbers are in black (black dial) use 2 for electronic flash. I don't recall the setting for red dial models..

Just checked my files and the red dial is set to 20 for electronic flash.

 

[Dez]

Replacing the RF mirror

Replacing the RF mirror

I was able to find a replacement RF mirror on ebay, and I recall that I was once able to get one from Edmund Scientific that needed to be cut down but did the job. You need an 8 x 10 x 1mm 50% semi-silvered mirror.
It looks like a difficult job, but it isn't really. Here's a string that contains instructions for the job.

http://www.rangefinderforum.com/forums/showthread.php?t=84849

Good luck,

Dez

 

[colyn]

I was able to find a replacement RF mirror on ebay

Good luck,

Dez

Here's a current auction for the mirror..

http://cgi.ebay.com/Leica-IIIf-IIIc-IIIg-Parts-Half-Mirror-New_W0QQitemZ160402090783QQcmdZViewItemQQptZFilm_Cameras?hash=item2558b5ab1f

 

[Dez]

I'm pretty sure that was the same vendor I bought my recent one from when I was fixing up my IIIb, which has the same RF as the IIIc/f. The part showed up pretty quickly and did the job just fine.

Cheers,
Dez