Questions regarging smoothnes of leica lens when focusing

[MP Guy]

I have a 35 lux asph which I just love. However, for the most part focusing is super smooth as long as you are turning the ring. However when you stop focusing and need to start again, it is always sticky and jumpy at the start. This is quite frustrating. Here is the oddity about this problem. It only happens when the lens is mounted on the camera. Turning the focus ring while the lens is off the camera is absolute perfection. Put it on the camera and it becomes sticky. Any clues?

 

[dreamsandart]

I had the same problem with mine. I sent it to Don at DAG and it came back perfect. He also adjusted the aperture ring so its more defined at stop/half-stop, I never liked the too easy to turn 'smooth' way it came from the factory.

 

[kevin m]

Here is the oddity about this problem. It only happens when the lens is mounted on the camera. Turning the focus ring while the lens is off the camera is absolute perfection.

I've had that problem with a couple of Leica lenses in the past, too. I have no idea why mounting the lens would change the focusing, but it does seem to happen.

 

[x-ray]

I had the same problem with my tabbed 50 summicron. It would freeze up at 3ft and was tough to get past that point but was smooth as glass off the camera. My 90 apo asph was sticky like that too and DAG relubed it and it's OK now but stiffer than before. My 35 v4 summicron is sloppy in the focusing helix too. I actually think leica is cutting corners on quality. I neverr had any problems with lenses made prior to the late 70's when they started having financial trouble. It's a known fact that the M bodies after the M4 had corners cut to save money for example the RF in the M4P and M6.

 

[Flyfisher Tom]

All lenses could do with a bit of lube now and then via a CLA by DAG or others.

One would not think of driving a car without changing the motor oil, yet we seem to think the lubrication on a lens should last forever.

DAG does good work, give him a shot.

 

[SteveM(PA)]

It could be that the base ring is slightly bent, maybe from taking even a slight hit or something, such that when the lens is mounted, it conforms to the plane of the lens mount, while becoming out of round in relation to the focus ring. This is the way Youxin explained it to me (my collapsible 'cron is like this) and he says the only way to fix is to replace the base ring, which he says DAG can do. It's like a dream off the camera (Youxin CLA'd it twice before he figured out the problem).

 

[peter_n]

New lenses should not behave the way Jorge has described. I've had two current Summicrons, a 24/2.8 and a 90/2 AA behave similarly. The 90/2 behaves exactly as Jorge describes. I sent it back to Tony Rose 3 or 4 weeks ago and I'm assuming that Tony sent it to Germany. I believe Solms insist on servicing the ASPH lenses themselves. Needless to say I'm not greatly pleased...

 

[edodo]

I think it is due to a lack of grease on the helicoidal. My experience is that the gravity will make the stiffness in the focus manipulation, that you don't notice when actioned on a different angle.