SL APO Summicrons stiff focus

[ravinj]

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I never used MF with my SL primes given the AF is extremely accurate. But just tried the MF ring on SL 50 (manufacture date Feb 2020) and SL 90 (manufacture date March 2019). Very well damped and smooth. No noise.

There is this right amount of resistance that I like, but it is not "hard" or "bad". The best I can describe it is Lexus steering wheel which is silky smooth, but kind of dead feeling with no feedback versus Mercedes Benz with just the right amount of resistance/feedback. MF on my SL primes is in the latter category with a solid reassuring feel.

The one Leica lens that does have silky smooth focus ring is the Leica APO Elmarit-R 180 - I can turn it using pinky finger. A bit too sensitive IMHO, but I was informed that this by design.

Edited June 20, 2020 by ravinj

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[rtai]

My new 28mm SL is so stiff I have given up the idea of manual focus. I’ll slap on an M lens when I want to do that. 

[RBB]

In response to this topic I picked up my SL Summilux to ty manual focus, indeed quite stiff, almost not to do. Put it on the SL2 and selected manual focus in the menu and suddenly a smooth manual focus. Took the lens off the camera and the focus ring is still smooth, no idea how this is possible??

[Photoworks]

The manual focus rotation is operated by magnets to determine the rotation direction 

[jrp]

I got my SL lenses more or less when they first came out.  None of them is smooth.  I thought that it might be an electronic thing, that they'd be smooth when I set focus to manual, but that doesn't seem to be the case.  Anyway, I haven't bothered to send them back though a combination of laziness and mainly using AF and fear that if they messed with the lens it would be less good than the stellar performance I am getting.

[rtai]

It is easier to turn if it’s on the camera set to manual but it isn’t smooth like the zoom. I can feel a lot of friction turning it and it isn’t like a tight M lens where you know it’ll ease up with use.

If only a small number is affected then it’s a defect but seems it’s universal so more like a feature. 

Edited October 2, 2021 by rtai

[DavidJohn]

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I'm about to purchase a prime for my SL2.  Will be getting it from a reputable dealer, and will try it out carefully, and inspect it, right away.  If it has any problems, it'll go back for replacement.  I don't want to send it to Leica and do without it for months while they fix it.  One dealer offers a 14 day return, and another a 30 day return (for exchange or store credit).

If I can find one used, my local dealer offers a 7 day return.

 

[LBJ2]

On 12/29/2019 at 4:44 PM, LocalHero1953 said:

My Apo-Summicron-SL 90 was very stiff. It has gone back to Wetzlar for fixing, agreed to be free under guarantee.
It was first appraised by Leica in London, who agreed it was too stiff, then Wetzlar confirmed it would be a free fix once it had been received there. I didn't have to argue.

I know this is an older thread. Where you given a reason why your SL 90 focus ring was too stiff to begin with and what they did to fix it? 

[LocalHero1953]

21 minutes ago, LBJ2 said:

I know this is an older thread. Where you given a reason why your SL 90 focus ring was too stiff to begin with and what they did to fix it? 

Sorry, no - no feedback at all.
An update on the post you quoted: it was returned from Wetzlar to Leica London, who decided it was still too stiff (they didn't ask me!) and sent it back again. It came back looser, but not what I would call moving freely. 
TBH the issue hasn't crossed my mind since: I use the lens only in AF, so the stiff manual focus is not a real-world problem.

[LBJ2]

2 minutes ago, LocalHero1953 said:

Sorry, no - no feedback at all.
An update on the post you quoted: it was returned from Wetzlar to Leica London, who decided it was still too stiff (they didn't ask me!) and sent it back again. It came back looser, but not what I would call moving freely. 
TBH the issue hasn't crossed my mind since: I use the lens only in AF, so the stiff manual focus is not a real-world problem.

You wrote "It came back looser, but not what I would call moving freely." Thank you that's part of the info I was wondering about your repair. Seems the SL prime focus resistance is probably intended as part of the SL focus ring magnet design. I have three SL primes all new production dates and all three are about equally resistant but very smooth and precise. But more resistant than any AF lens, I've ever used. 

[LBJ2]

I am probably the last person on this forum to read this, but thought I would post for anyone else just discovering the SL system and the SL prime focus ring build and maybe the reason for more resistance when using the focus rings...maybe

"Manual Focusing
A new experience

SL-Summicron Lenses feature a totally new manual focusing ring construction concept. In this concept, a ring magnet with alternating north-south magnetization is embedded in the manual focusing ring. The magnetic field changes its polarity when the ring is turned. A sensor monitors the status of the magnetic field and sends the data to the main processor. The drive then shifts the lens to the corresponding focusing position on the basis of the angle of rotation and the rotational speed.

The construction of the MF-ring guarantees reliable sealing against dust and water spray, provides protection against impacts and other mechanical stresses, and prevents focusing inaccuracies as a consequence of temperature fluctuations. Even after years of use, the MF-ring of a SL-Summicron lens impresses with a smooth action without play and homogeneous focusing."

https://us.leica-camera.com/Photography/Leica-SL/SL-Lenses/Prime-Lenses/APO-Summicron-SL-90

[LocalHero1953]

I........see!

Explains a lot. I can understand the rationale, but maybe they need to reduce the strength of the magnets a bit.

Thanks for the link.