50mm Summicron - Focussing ring tight

[kingsley1]

I bought a used 50mm Summicron for my M6 some time ago, the late type with the

built-in hood. I used it recently and found that the focussing ring is too

tight. It is difficult to get a fine adjustment as much force has to be put on

the ring to turn it. What could it be and how could I solve this problem ? The

lens looks brand new.

[paul hart]

I had that problem with a chrome current model 50 Summicron I used to have. It had to go

back to have it sorted. The only suggestion I can make short of that is to work it to and fro

for a few minutes. You might be able to do it while watching the telly without getting too

many funny looks.

[john_shriver]

Could be that the grease was always, or has gotten, too thick. Simple clean, lube, adjust project.

 

Could that the lens has been dropped or bashed, and the focusing helical is bent, in which case it's probably not economically repairable.

 

If it worked nicely when you got it, it's probably the former problem. (Unless there are demon squirrels in your house!)

[paul levin]

I recently acquired a 50 Summicron with the same problem. (Circa 1979, Canada, tabbed)It actually was fine when rotating the focus from infinity down. But if I overshot the focus and had to go back in the other direction it stuck just enough that when enough force was applied to get it moving it caused a stutter and overshot the focus point. I sent it to DAG for a CLA. That eliminated the problem. It came to $75 plus return shipping. YMMV

 

Paul

[anthony_brookes5]

Before you pay a not inconsiderable sum for a clean it is worth warming the lens slightly - near a radiator - and then working it to and fro for a number of times. I did this with a 35mm Summicron and it works fine now.

[35mmdelux]

Needs to be luded. Send it to Sherry.

[stephen_w.]

Is the resistance constant? I had a stiff ver. 1 35 'cron that I sent to Sherry for a tune-up. I told her not to loosen it up too much, as I liked it that way. She did her normal CLA and took out all of the old lube and restored it to "factory" spec, oh well.

[kingsley1]

Sent lens to be lubed. Thanks to all for the responses.

[kelly_flanigan1]

A lens that has been dropped will often be stiff; the focus helix then is slighlty oval shaped.