90 M-E-M focus problem

[nyx]

Hello,
I recently bought this lens (90mm Macro-Elmar-M) and it has following focus problem.

at infinity, it's spot on (tested on collimator)
at closest focusable distance (0.77m), it's consistently focusing around 1cm behind subject

Tried on two bodies (M6 and HRF)...it focuses equally wrong on both.

Is there any way to fix this? And who should be able to do it? (EU ideally) At local camera repair shop I was told they can do nothing about it - only suggestion was to make it front-focus at whole range, so it would be ok at close but off at infinity. And after they looked closely at the mount, they weren't able to do even this.

 

[awilder]

Before blaming the lens, I would try another Leica lens like a 50 Summicron to see if there is a similar problem at near. Are you going by the distance scale reading and if so are you measuring from the film plane and NOT the front of the lens? If the camera is at fault, there is an adjustment for close focus rf calibration at 1 meter in both cameras and can be done by a competent Leica repair person in the EU or USA. You can even DIY with a little research on the web if you are somewhat skilled and a little brave. I don't believe the lens itself is amenable to focus calibration adjustment at near without affecting distance as well.

 

[nyx]

Thank you

I checked on film shooting focus charts.

I'll try to borrow some other lens to test it with. Fastest / longest other lens I have is 50/2 hexanon and I don't remember having any problems with it (but maybe they were just too small to notice).

 

[awilder]

Double check infinity focus to make absolutely certain the M-E-M does not cause the camera's rf patch to overshoot infinity focus even if it's a tiny bit. To do this correctly, make sure you first set the lens for infinity endpoint BEFORE mounting and maintaining this setting when mounting. If the camera's rf patch focus overshoots exact infinity focus on a distant subject, adjust the rf cam roller screw as needed.

 

[nyx]

Ok, I returned from holiday and tried with my other lenses (50/2 hex and 35/2 biogon) - both of them are absolutely spot on at 0.7m.

So, what are my options now?

Sending it to leica to change half of the lens? Any idea how much it could cost?
Adjusting focus on my camera? And preferably, use only this lens and wides on the body?

Any other ideas?

 

[awilder]

If your are certain the lens is off at close focus, return the lens to the dealer for exchange if new and still under their exchange policy (if they have one). Another option if new and covered by Passport warranty, return it to Leica for exchange but also include sample images from the M-E-M and your other lenses to explain the situation. If not covered under warranty, have the camera's rf adjustment checked at both infinity aand 1 meter to make sure it's to exact spec. If none of the above works for you, adjust the camera's rf to slightly front focus with the M-E-M to more accurately focus at 0.77 m if that's critical for your needs. I don't think it's possible to partially adjust the focus accuracy for either end of the range or the other, it's all or nothing.