Leica 50mm DR Summicron
I'm looking at two 50mm DR Summicrons. One says 5cm with GmbH inscriptions are upper and lower case; the other says 50 (no units or GmbH) and all the inscriptions are upper case letters. Distance scale on the barrel are also different. Did Leica make two versions of this lens? I tried searching for any information regarding this, but am not making much progress. Hopefully one of you knows.
Ah. I think I figured it out...
in the 1940- and the beginning -50-years it was usual to use the old unit system wit cm instead of mm (the German 8.8Flak also had a caliber of 8.8 cm, not 88 mm). I cannot say when Leitz did change from cm to mm, I have a 5 cm Summarit, a 5 cm fixed Summicron an a 2.8/50 mm E 39 Elmar. The distance scale could be only in meter or only in feet or lateron both.
Leitz changed the cosmetics of this lens (DR Summicron) at some time during the production run. Most notably, the shape of the focusing ring, the measuring unit of the focus length, and the distance markings were changed. The older version has distances marked either in feet or in meters, while the newer version has both. Optically there should be no difference between these lenses, although it might be that the coatings were changed a bit during production of this lens, I am not sure about that. Whatever version you get, make sure the glass is scratch free and without haze inside. The glass and coatings of theses lenses is very prone to scratches and pitting. Internal haze will sometimes only show up when looking through the lens against a bright light source (flashlight). Haze will lower contrast and make the lens flare when shooting against the light. While internal haze can be cleaned sometimes, there is no guarantee a cleaning job will save the lens. If you luck out, the glasses are already permanently damaged and nothing can be done. So better to get a lens that is free of haze right from the start.
One more thing, Make sure you get the "goggles" together with your lens, they tend to be scarce and pricey as a separate item, and you run the risk of ending up with goggles that don't fit your lens, as there is a difference in the mount of the goggles between the older and the newer iteration of the DR Summicron.
Excellent information on this topic can be found here.
Thanks, jochen and mnnemosyne! I was comparing my version with another, and it seems I have the later version with the dual distance markings.
On a side note, the goggles that came with mine are broken. The round lens that goes over the rangefinder is loose in its holder, so the images aren't aligning properly during focusing.
The round lens is the one used to adjust the image.
There should be a screw in collar in front of the lens. sometimes the ring can be tightened by using a pencil eraser. Use the side of the eraser against the ring.
If that does it, it's just trial and error to set it. You should be able to see the image move as you rotate the lens.