Voigtlander Nokton Classic SC 35mm F1.4 - Stiff focus ring when mounted on M6

i all,

 

I just recently picked-up a very slightly used Nokton Classic SC 35mm F1.4 lens. When the lens is not on my M6 the focus ring turns quite nicely (i.e., free but damped). When I mount it on the camera, however, the ring now becomes very stiff to turn making focusing difficult. (FYI: my other lenses don't do this when mounted on the M6.)

 

Is there some way to adjust or lubricate this?

 

Thanks in advance,

Danny

Email Don Goldberg ("DAG") at dagcam[at]chorus[dot]net

Email Don Goldberg ("DAG") at dagcam[at]chorus[dot]net

Thanks for the advice!

Loosen slightly & equally the four screws facing you when looking at the mount.

Mount it to your M6 and see if the focus ring is loose, if it did loosen, then the mount on the lens has been warped.

 

Try torquing them down progressively in a cross pattern as to even out the pressures on the mount.

If this doesn't remedy the issue, then get it to a competent technician:

The lens either sustained a shock or impact, or someone overtighten in wrong manner and created the issue...

I should have realized "the great Gus" would have the answer (he's definitely one of those 'compitent technicians' to which he refers).