Anyone know what this screw does on the Rokkor 40 mm lens?

[panerai]

Just got this lens, but seems to be a little more play in the upper barrel section than another I have.

Thought maybe the screw tightens up the barrel (only one visable), but thought I would ask first before screwing it in (did a little, but decided to put it back where it was before doing something I shouldn't)

Thanks

DON

 

[FrankS]

I doubt that it tightens up the barrel. That is more of a function of the grease on the focusing helix. You could try to tighten this screw, but I'm sure that you'll find that it is already secure and unable to tighten further.

 

[panerai]

I doubt that it tightens up the barrel. That is more of a function of the grease on the focusing helix. You could try to tighten this screw, but I'm sure that you'll find that it is already secure and unable to tighten further.

Hi Frank,

Thanks. Actually it did go in a bit more, but didn't want to go any further in case it held something together and further in it could seperate from the main barrel.

Do you think I should move it in further until it stops?

Regards

DON

 

[FrankS]

I am not competent to give that kind of advice.

 

[panerai]

I am not competent to give that kind of advice.

Thanks again.

I did try, but it was going too deep and decided to back it out to avoid it dropping inside

Think I will leave it alone before I end up with a paperweight

Regards

DON

 

[monopix]

A single screw is unlikely tighten the barrel as it would be uneven. There would normally be three around the barrel. I suspect this is probably the infinity stop or something similar.

 

[t6un]

My Summicron-C has similar one, and another one opposite to it. As it's on aperture setting ring, it probably either connects it to the aperture or limits it's travel.