Focusing with CV lenses on an M6

[putnasaur]

I just received an adaptor ring to mount my CV 15mm and my CV 28mm to my M6 (it is an Adorama 15,28,90 ring). Today I put the 28 on the ring and noticed the hyper focusing dot on the middle of the lens is slightly to the left. When I tried focusing on a hill top about 500 metres away, the lens wouldn't go all the way to infinity. Is this normal? Did I put the ring on wrong? Any thoughts?
Thanks.

 

[leicaman83]

First check to see if another lens reads infinity on the same hill.

LSM lenses will sit slightly to the left of center on a screw mt camera or adapter on an m.Focus is normal, but the scale is off to the left.

Make sure there is no debris on the mating surfaces of the lens or adapter. Some cheap adapters are not the required one millimeter thick. If yours is too thick, the lens will not reach infinity. A micrometer is required to measure the flange thickness. There could also be dirt on the cam of the rangefinder or lens.

I have had the best luck with real Leica adapters and the CV ones. I have measures and compared and the CV ones are perfect.

 

[putnasaur]

Thanks for the response. I figured the focus was off to the left during my shoot yesterday. I don't do much infinity focusing, most of my shots are hyper focused at f/5.6, f/8 or f/11. Will this affect it if, say, I had the lens at f/11 and hyper focused with infinity at 5 meters?

 

[putnasaur]

Thanks for the response. I figured the focus was off to the left during my shoot yesterday. I don't do much infinity focusing, most of my shots are hyper focused at f/5.6, f/8 or f/11. Will this problem affect my photos if, say, I had the lens at f/11 and hyper focused with infinity at 5 meters?

 

[leicaman83]

I really can`t say as you never said how much off the infinity focus was. Usually if you use hyper focus , there are errors anyway but they are covered somewhat by debth of field. But that is some what a myth. I never was happy with hyper focus.

Learn to focus by feel and befor you raise the camera to you eye in street situations. Practice.

 

[putnasaur]

Hyper focusing is the way to go around here. I'm in Baghdad and not only is specific focusing difficult while under fire, it takes too long and the people here will ruin those candid moments I'm aiming for. But I appreciate the advice nonetheless.

 

[peter_n]

Bill I have used Leitz, CV and Adorama adapter rings and they have all been perfect. I would agree with Ronald that hyperfocus can be dodgy, I use a 28mm Nikkor on my M6 with an adapter and there is no rangfinder coupling so I use hyperfocus and DOF does not take care of everything especially when the main subject is pretty close.

You will have no problems with the 15mm, but with the 28mm you might want to keep the aperture as small as possible, and as far as I can remember total DOF is split with 2/3 of it behind your subject to infinity, and 1/3 is between your subject and the camera.

A 28mm at f11 should give you DOF from 1.2 metres to infinity, with optimal focus at 2.44 metres (this from the Morgan & Lester Leica Manual & Data Book). Just checked that with my Nikkor and it looks about right from the lens barrel. Remember most of that DOF will be behind your subject.

Stay safe in Baghdad, Bill!

 

[putnasaur]

Peter,
Thanks for the tips, man. I've been shooting everything here at f/8 or f/11; every so often I have to use f/16 or f/22 because its so damned bright out here. I shot a lot of stuff yesterday with Agfa 25 ASA B/W; my focusing worked great. The exposures here at f/11 are 1/30 or 1/60 in bright light or shadows. Anyway, thanks for the tips and I'll let everyone know how the images come out when I get home -- next year (ugh).