somewhat loose aperture ring in newer 50mm Summicron M

[andrew_schank]

I recently bought a early 1990's vintage 50mm Summicron with the focus tab (and before the built in hood) I like the compact size and quick focus, but the aperture ring requires much less effort than I am used to with my other Leica lenses, and rotates fairly freely clicking into the half stops. Is this normal? The lens works well and seems very sharp. I'm a bit miffed that this "mint" lens has a tiny mark on the rear element, but such is life in the used Leica purchasing world.

[albert_smith]

Andrew,

 

<p>

 

I have the same lens, serial number 3359XXX, and it is a lighter

touch than my 35mm Summicron and 90mm Elmarit M. I like the external

hood and focusing tab, so this will be my 50mm lens for picture

taking. You just graze the aperture ring and it rotates freely, but

in practice, I don't mind.

 

<p>

 

I also have the 1969 model serial 2339XXX, that I got with my M4 and

it is tighter, but I honestly don't use it much... it doesn't have

the tab.

[andrew_schank]

I had a feeling that was normal. I now remember a Leica technician

telling me they made the apertures a bit looser on the newer lenses

because some of the older ones were prone to freezing up because they

had such a snug tolerance. The focusing tab really is nice so I went

out of my way to find one of that series. I found there to be a much

greater availability of the older 50mm lenses and the current series

ones _ I had a hard time locating one. that's why the mark on the

rear element got me mad (I know it won't have any effect on the

performance) By the way, do you use your thumb or index finger on

the tab for focusing, or both? Do you know if it is possible to

disable the infinity lock on the tab on my 35mm 2.8 Summaron?

[albert_smith]

I use the left index finger on the tab. I make an "L" out of my

thumb and middle finger... thumb on side, middle finger on bottom, my

index finger curls right up to the tab.

 

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I disabled my infinity lock on my old summaron (the type in which you

push a small circular button aft) by grinding the half circle down on

the side that allows the lens to focus, keeping the other half as a

stop. This allowed free swinging of the focusing mount. This was

the plan I opted for, deciding not to cut off the button and spring.

There was no adverse effect... I don't get infinity locks.

[Rob F.]

I've got the same lens, the Summicron-M with the focus tab, sr. no.

3021xxx, canadian version. The aperture ring does seem to glide

along just a bit smoother compared to my 1969-79 Summicron. But I

wouldn't describe it as "loose" and it doesn't take any less effort

to move it between clickstops. The effort required is about the

same. The clickstops feel about equally firm. It does require less

turning effort than my 35 Lux, 35 1960's vintage cron; and a good

deal less than my 90mm Elmarit. The latter three don't have

the "gliding" feel of the Summicron-M; the 70's model has some of

that feel. Mine doesn't seem abnormal.

 

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Regards,