Focusing Loose/Tight, 50 Summicron v. 90

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I have 2 Summicrons, the 50 and the 90, both -M designation. The 50 is German, chrome, the focusing is very loose and easy. The 90 is Canadian, black, and the focusing is rather tight. Both are extremely smooth but I prefer the looser feel of the 50. Has anyone noticed a correlation between focal lengths or places of manufacture insofar as this is concerned? Will the 90 loosen up? Can it be made looser?

-- Peter Hughes (ravenart@pacbell.net), September 28, 2001

Answers

I had a Canadian 90TE that was very tight, yet older German lenses that were not. My newer 90 seems a little tighter than my other lenses, but still very smooth. Lubricants can gum up as they get older, especially if they have been exposed to prolonged heat, so it is possible that your 90 needs a CLA.

-- Jack Flesher (jbflesher@msn.com), September 28, 2001.

For some reason many of the 90mm Leica lenses require stronger fingers to focus. My Elmarit requires more pressure to turn the focus ring than any of my other Leica lenses, and it was like that right out of the box. I would caution against messing around with the lubricants. I fooled around once on an old Nikkor that was too stiff, and a lighter grade grease I put in actually made the focus stiffer.

-- Andrew Schank (aschank@flash.net), September 28, 2001.

my new 90 F2 APO is also very tight. Yes, will it become loose later on? I like the feel of the Nikon 100 F2.5 AI, it is just right.

-- tom tong (tom.tong@ckh.com.hk), September 28, 2001.

My Elmarit has been used for 4 years now and is still just as stiff. I think you just end up living with it.

-- Andrew Schank (aschank@flash.net), September 28, 2001.

I've been using my 90 Elmarit for 40 years. I'd describe it as "firm" but not tight. It seems just firm enough to stay put without accidently rotating.

-- Bob Fleischman (RFXMAIL@prodigy.net), September 29, 2001.


I think all the Leica teles are somewhat tighter than the short lenses. Several people have commented on other threads about how VERY tight the 75 is.

Main reason, IMHO, is that you are moving a relatively heavy chunk of glass with the teles (possibly excepting the 135 f/4). In addition some have theorized that the extra damping helps slow down the focusing to make critical focusing easier. And, of course, if you are shooting with the lens tilted up or down the stiff focusing prevents focus creep with that same heavy glass, so it may be intentional.

When I had a G2, I could hear the AF motor really straining when it had to move the 90 way out for close focusing, and that is a relatively light lens compared to most Leica M-teles.

-- Andy Piper (apidens@denver.infi.net), September 29, 2001.


I'm with Andrew about leaving the lens alone. Leitz (in any factory) used very specific greases for their lens helicals and there were reasons for everything. None of the 90 Summicrons/75 Summiluxes I've ever seen had a loose focus, and I'd be concerned if they did. Not only is there a lot of glass, but the tolerances need to be extremely tight to maintain focusing accuracy with a rangefinder. On the other hand, this is one reason the 105 Nikkor can be so loose. Ever notice the image shift in an SLR finder with an old loose Nikon lens? You wouldn't want this happening with a Leica M (not that you could SEE it happening, but you'd notice your out of focus pictures) Anyway, hope this helps.

-- Carlin Mayer (carlinm@abac.com), September 29, 2001.

I belive Letiz tends to make longer lenses (90,135) tight, and shorter looser.IMOO

-- r watson (al1231234@hotmail.com), September 29, 2001.

Comparing my 50/2 DR and 50/2 lattest version, DR is much thigther than newer one, of course it makes it slower to focus, and DR has just been serviced by Leica in NJ, lattest one is a joy in my hands, just wish I could get the scewable shade of the new Elmar, I donīt like much the collapsible of the new one.

-- r watson (al1231234@hotmail.com), September 30, 2001.

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