Improving rangefinder contrast

[abruzzi]

i recently got a Watameter II rangefinder that I’m going to use with a scale focus Voigtlander Bessa. The Watameter is in excellent condition but the rangefinder patch is barely visible. I experimented with several filters I have, holding it over the main viewfinder to see if it improved visibility of the rangefinder patch, which it seemed to primarily by darkening the main view. I’m hesitant to put a filter over the rangefinder window because it’s already so dim, but what are the best options for the best contrast? I plan to buy a gel filter that I can cut down and install semi permanently.

 

[Pentode]

I’ve never tried this myself so take it with a grain of salt but I’ve read that if you place a small piece of tape the size and shape of the rangefinder patch on the main viewfinder lens (black tape is recommended), it will improve the visibility of the RF patch.

I’ve been meaning to try it on my Nikon S3, which also has a dim RF patch, but haven’t gotten around to it.

I imagine gels could also be used to control the degree of the effect.

 

[OptiKen]

I have taken a yellow highlighter to the patch only and it improved the contrast a lot. A black sharpie would probably be better but I didn't want to do anything permanent to the camera in case it didn't work.

 

[Mackinaw]

I’ve never tried this myself so take it with a grain of salt but I’ve read that if you place a small piece of tape the size and shape of the rangefinder patch on the main viewfinder lens (black tape is recommended), it will improve the visibility of the RF patch..

This does work, I tried it on my old M3. Only drawback is that you see a fuzzy black blob in the viewfinder as you look through it. If you can ignore the black blob, focusing is easier and more precise.

Jim B.

 

[Pentode]

This does work, I tried it on my old M3. Only drawback is that you see a fuzzy black blob in the viewfinder as you look through it. If you can ignore the black blob, focusing is easier and more precise.

Jim B.

I wonder if the two ideas could be combined; if a small center spot of gel was affixed to the viewfinder window instead of tape maybe it would still improve contrast and accuracy but not appear as a black, fuzzy blob. And if that actually worked, I wonder what color gel (or ND) would work best.

 

[Dan Daniel]

I A black sharpie would probably be better but I didn't want to do anything permanent to the camera in case it didn't work.

As a side note, alcohol will remove Sharpie ink, especially from non-porous surfaces like glass.

 

[guangong]

I have a accessory filters made by Leitz for my IIIa and IIIc cameras. Typical of Leitz, different models require filters of different sizes that fit over the rangefinder window. The filters are a very light orange. This might be a place to start.

 

[EdSawyer]

have you cleaned the mirror and internals? That would be a worthwhile start.

 

[abruzzi]

I haven't disassembled it--afraid of accidentally destroying it--but from the outside everything seems pretty clean. The device and it case actually seem almost unused. I have adjusted the randefinder because it was pretty off when I got it.

 

[dmr]

have you cleaned the mirror and internals? That would be a worthwhile start.

Watch out! If there's a front-surface mirror in there you will ruin it by trying to clean it! I found out the hard way.

 

[EdSawyer]

It's definitely possible to clean a first-surface mirror without damage.

 

[dmr]

It's definitely possible to clean a first-surface mirror without damage.

Ok, how?

I tried it with a damp q-tip and wiped the reflective coating off! Fortunately another RFFer had a spare and sent it to me. This was on the Mamiya SD RF.

 

[abruzzi]

I’ve long since come to the realization that except in a few specialized fields, any repairs I attempt makes things worse.

I did fond on eBay a gel filter sample book. I figure that may let me experiment with combinations to find an ideal mix.

 

[EdSawyer]

just a soft dry microfiber cloth for optical use will clean most 1st-surface mirrors just fine, in my experience. (Rollei, graflex, kalart, Voigtlander, mamiya, etc.)