M Lens adjustment

[Bill Caulfeild-Browne]

I have six M lenses from 21 mm to 135 mm. All but one focus perfectly. When the lenses are set to infinity (or any other distance) the rangefinder is completely aligned and the pictures are very sharp at full aperture. From this I deduce that the rangefinder and five lenses are properly in synch.

The one that doesn't is a 75mm Cron ASPH that was adjusted by Leica USA some time ago. It has clearly become "un-adjusted". The lens is perfectly sharp when set at the infinity mark but the rangefinder moves past the infinity setting. The lens cam moves too far in when the lens is set at infinity.

Question: I'm pretty handy with camera mechanics (having rebuilt a few) but before I try to adjust the cam, does anybody have any know-how or suggestions?

Thanks,
Bill

 

[gogopix]

Look around the rangefinder forum or google. I remember that there is an adjustment for the camera to the side of the RF opening that can be adujsted.
But But But

if all other lenses are ok, then it is the lens, and for that it is either trivial or insanely difficult (so rumour has it)

If the 75 (discontinued isnt it? or was that the lux?) is off at infinity, then the infinity 'stop' is off, if you loosen the barral screws near the focus ring, you can focus at infinity and then put the 'bowtie' at the index for distance. On some lenses this will reset the infinity stop. SOme lenses actually do not have an infinity stop, to allow focus in different climates and extreme weather (like the 35-70/2.8 R lens)

Some lenses are, as I said, SUPPOSED to be easy to adjust (I believe Robert, an R lens expert did it and even said how.

Good luck. If it were me, I would send it back to Leica.

best regards
Victor

 

[Bill Caulfeild-Browne]

Thanks Victor. There's nothing wrong with infinity focus. When the bowtie is at the index, focus is perfect - but the rangefinder image goes beyond synch. It's the cam in the lens that's the problem.

I'll do a little more investigation on the Web.

Bill