Anything wrong with Summicron 90/2 on R3A?

[Jochan]

I just bought a Summicron 90 for my Bessa R3A but I think there is imcompatibility on the Bessa with large aperture F2. (That's why CV 90 has F3.5 only). In my fist roll, I found some pictures are out of focus as using F2 and F2.8 but some are ok. 😕 I am not so sure about this maybe the out of focus are caused by my bad focusing skills. Could anybody tell me about any imcompatible on Bessa and Summicron 90/2?

 

[Nikon Bob]

I have not heard of any incompatibility issues in that it will mount and work properly. I have heard it speculated that the Bessa might not have a long enough rangefinder base length to focuss a fast 90mm, especially wide open and at close distances. Maybe this is what you are experiencing?

Bob

 

[rover]

I guess Mr Puts can tell you the EBL requirements to focus your 90/2.

http://www.imx.nl/photosite/leica/technics/rfaccuracy.html

I would suggest also to experiment with the lens and use it away from the limits of the camera. Use it for objects at a little distance and not wide open, and slowly move in closer. In that way you will be able to see what limits you find with the camera and figure out how to deal with them.

I always found using the 75/2.5 on an R or R2 to require greater care in use when upclose and open, but in more general situations those combos worked great.

 

[Jochan]

Thanks, Bob. Could you explain more? You mean when the len is wide open(F2), it cannot focus well?

 

[Jochan]

Thanks Rover. That is a great article, I know more about the ability of RF (the weakness). In that case, a fast long lens doesn't have its advantage on RF. So sad to hear that :-(.

 

[Huck Finn]

Jochan, CV only has a 90/3.5 because it didn't have the R3A until 6 months ago. The limit for a 90 mm lens was caused by the base length combined with the magnification of .68 on the R and R2. With the increased focusing capabilities of the R3A due to the increased magnification, the time is right for them to come out with a faster 90 mm lens - & I suspect they will.

Focusing on the R3A should be adequate for the 90/2 - not great, but adequate. I think that Rover & Bob have spelled out the issues. I suggest that you keep practicing. It is tricky to focus a 90/2 up close & at full aperture in the best of circumstances. Best of luck with it.

Huck

 

[spetsnaz]

I've got the same with my R2, a slightly back focus if I didn't take a great care of focusing. R3A 1:1 viewfinder should make it easier but that "great care" still needed.

Cheers,
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