I recently became the owner of a used GS645S, in decent condition. This is my first medium format rangefinder, so I was naturally stoked (I have a weakness for rangefinders, especially well-built ones). Now, the camera is not quite a Leica. In fact, it is more like an old Polaroid camera – lots and lots of plastic. But the lens seems decent enough, based on reviews online. I am still on my first roll, so I can’t really comment on it yet. What I do want to comment on is the terrible rangefinder patch! The patch is small and the contrast is absolutely terrible. This has made focusing exceedingly difficult. Based on my recent experience with a Leica IIIa with very poor contrast, I tried to stick a piece of colored gel on the viewfinder to improve contrast. Although it did help somewhat, it also made for a very distracting experience – I simply couldn’t get past the green/red view on the finder.
I was about to give up on this, when a final search yielded an interesting solution – an ND filter! I was skeptical, but having tried it, I can say with confidence that this is the best solution out there. Non distracting, and supremely practical. Who would have thought that a viewfinder can be too bright?! 🙂