Focus Cam stick out to far? Any Ideas from M experts?

[rardinger]

I just ran across an issue I had not encountered before and would appreciate some assistance.

I just bought (via the internet) a like new in box previous generaton (seperate hood) 50mm f/2 summicron. The lens is immaculate and off camera "fondling" gives no sing of any problems.

The focus ring goes cleanly from the close mark to infinity when not on a camera. However, I had the lens set at infinity (no real reason) and mounted it on my M6 and it was a bit stiff to mount but did click into place (no real force, just more effort that usual). Once mounted the focusing ring would not move. Took the lens off and all seemed well. Mounted it but at the close focus setting as I was wondering about the lens cam and wanted to move it inward. Lens easliy mounted, focus ring moved freely BUT it was focused at infinity (acording to the rangefinder) when the lens was set at about the 25 foot mark. The focus ring would not move any further toward the infinty mark.

I remounted my other M lenses, all are the same to each other, all mount well, all focus to infinty. I went back and forth from the 50 to the others and the 50's scale was constantly off. if a 35 or 90 was in focus at a subject 10 feet away, the lenses said 10 feet. If the 50 was focused on the same object, the lens said about 8 feet (between 6 and 10).

Basically it appears the focusing cam it just a bit too long (deep?) for the lens setting . It is moving the camera rangefinder arm deeper into the body than is correct and with the 50 is at 25 feet the camera arm is in all it can go.

I tried this lens on a Bessa R3a and the camera cam must go into the body further than on an M as the lens will move from close to infintiy without any binding BUT when the Bessa rangefinder locks onto a distant subject (infinity - clouds) guess what, the lens scale is at 25 feet, moving the lens to infintiy overshoots the rangefinder and the images are not aligned (this bessa and the M camera are fine with my other M lenses).

I will likely return the lens as I have only had it for a few hours and the seller appears very reputable but I wondered if anyone else had encountered this before and if so was the fix simple (an adjustment) or painful (rebuild).

FYI this is a model 11819 summicron, canada built, plastic hood, red and blue and white box (with same serial number) and was thought to be unused (likely 20 to 25 years old) (no cards, plastic or seal on box however). I think this is not a personal lens of the seller (one that he used without issue). The condition of the lens is truley mint which make the focus issue all that much more sad.

Thanks,

Robert

 

[Kim Coxon]

This sounds very much to me as though the lens has had a re-lube and the helix has been inserted on the wrong thread. If this is the case, it should not be difficult to get repaired. However, it is not something I would suggest attempting unles you know what you are doing.

I would contact the seller and see what he says. Depending on the price you paid, it may be possible to come to a compromise.

Kim

 

[Ben Z]

I agree on the cause, but the bigger issue is that no competent repairman would've done a lame hackjob like that, so you've got to wonder what else he loused up, like putting inner elements back inside-out, stripping the helix while fumbling it together, heaven only knows. Probably a guy like DAG could get it back together right for $100 or so but you never know 'till he sees it, so if you've got a limited time you can return it that might be a problem. If it were me I'd return the lens for a refund. They're not rare, another one will come along.

 

[jaapv]

That is sound advice, Ben

 

[rardinger]

Thanks for the suggestions. In this case the seller was and is above reproach and there is no problem with return/refund. It was more that the lens does look essentially new, no tool makes, perfect glass, no paint chips that I have hard time thinking it had been inexpertly worked on. It is an older vintage so I suppose it could have been serviced in it's past, misaligned then and not used until now. I have had a "hacked" 135 lens (mismatching head and focus assembly) but it was older and looked used. The seller will send the lens to be repaired. I had just never come across this before and have had/used many M lenses over many years.