Collimate Summicron Collapsible

[Stu W]

I noticed that my collapsible Summicron 50mm is slightly out of calibration. When shooting with a wide open aperture the point of focus is slightly off. Not very noticeable stopped down. I checked the camera using the slr method and found that the lens is ever so slightly off. It misses making infinity by probably less than 1/8 inch of turn on the focusing ring. At infinity it doesn't really matter but up close that 1/8 changes my point of focus by 4 or 5 inches. I checked 2 other lenses and they were right on the money, so I know it isn't the camera body. Is the lens cell on the Summicron adjustable? I really don't feel like sending the lens out, especially since it was cla'd not so very long ago. Thanks. Stu

 

[John Shriver]

I had my LTM Summicron apart recently, and I didn't see any provision for adjusting the collimation. There's no shim in there to change out, or lose. I suspect that they file the barrel of the focusing mount to length! My lens is from the first two years of the Summicron, which was definitely still the "adjust to fit" era at Leitz.

Perhaps your helical is assembled on the wrong start(s)? Not at all unlikely during a CLA. Does the RF cam protrude the right distance at infinity (7.5mm on LTM, 6.5mm on M)?

Or, perhaps you have a mutt. Parts of two lenses put together, not of the same focal length group. My lens block is scribed 51.9, for 51.9mm focal length. Looking at Erwin Puts Leica Lens Compendium (now available free on his website), that's focal length group 8, which is 51.9mm. There's an 8 on the back of the infinity lock on my Summicron. So my lens is not a mutt.

This is also a very common problem with the removable head rigid Summicrons, mismatched serial numbers between the lens and the focusing mount. Particularly common trick to "fix up" an LTM rigid Summicron, which is rare, swap in the lens block from some M mount rigid Summicron that isn't all cleaning marked or hazed out.

 

[Harry Lime]

I sent mine to Leica in New Jersey. For about $80 bucks they did a total rebuild. The improvement is amazing.

Harry Lime


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