Leica CV 75/2.5 front focus calibration...help :)

[uhoh7]

I have the CV 75/2.5

It will not reach infinity on my M9 with any of four LTM adapters.

I removed the back plate but no shims in sight.

No obvious screws on the side. I tried to unscrew front cell a la Canon LTM, but either it's on there really tight, or it does not unscrew.

Where are the shims?

TY in advance

 

[Brian]

What does the actual focus do? Does it agree with the RF at min and max throw? How far is it off? Can you unscrew the rear group? Polish down one of the LTM adapters so the lens screws in closer to the image plane?

 

[uhoh7]

TY for reply, Brian

The lens front focuses by several inches at 2 meters. I'd hoped there would be shims behind the LTM mount, but no. It may unscrew but seems really tight. I should ask DAG.

I have though about grinding a LTM adapter, but wonder how to accomplish this evenly out side a machine shop. Would be nice if somebody offered these at various thicknesses.

this is the lens:

CV 75mm by unoh7, on Flickr

 

[Brian]

I use a solid/flat surface, put a box in it, lay a sheet of very fine grit sand-paper on it. Smooth, circular motions, and check with digital micrometer.

How is the focus at infinity?

 

[uhoh7]

I use a solid/flat surface, put a box in it, lay a sheet of very fine grit sand-paper on it. Smooth, circular motions, and check with digital micrometer.

How is the focus at infinity?

Well you hit the mark but it does not quite make infinity on the M9. On A7 with adapters that go past infinity it does.

With some english I can still focus it

L1043037 by unoh7, on Flickr

 

[Brian]

See if you can unscrew the rear group slightly. That will get t to infinity, and slightly increase the focal lenght.