Focus shift - camera or lens?

[woonder]

Hi all,

I just got a second-hand R-D1 recently. The camera works fine with my 3 50mm lenses: the old Summitar, Hexanon and Canon 1.4 LTM.

So I got happy and acquired a Zeiss 21mm Biogon f2.8. Bad luck, the lens front-focuses at near distances (<3m).

Then I got the CV 40mm 1.4. Strangely this has back-focus. I couldn't even align the rangefinder patch when focussing at objects at infinity.

Does it mean my camera is wonky? Or just my luck with the lenses?

Many thanks!

[mfogiel]

You should first check the rangefinder with a lens that you know focuses well. Most likely, the rangefinder is off, as this is the most obvious cause. Then, you should check your lenses. The LTM ones are often all over the place, also because of the adapters.

[tuanvinh2000]

sounds like a rangefinder misalignment to me. Try with other lens focusing at infinity objects to see if things align (i always aim for the roof of the tallest building). i have the biogon as well and since it's a 21mm, i dont even use the patch and guess all the time. mine has issues focusing a 50 lux but no issues with the cron.

[woonder]

Thanks for the replies guys. Guess it's going for some realignment.

[Rangefinderfreak]

Most lenses suffer sometimes of "focusing glitches" even leitz lenses. If you want to be sure you have your set-up propely aligned, you should first have your bodies calibrated, prefarably by a qualified service technican in a collimator. Both the Voigtländer and Zeiss M lenses are reasonably easy to adjust, just shims between the lens cluster and focusing helicoil. The leitz lenses have to be sent to factory...VERY expensive ! The reason here is that in the past, with film bodies, this was not an issue, but with digital bodies it is...

[willie_901]

I think Rangefinderfreak's advice is spot on.

The mechanical mating between the lens mechanism and the camera focusing cam is not always identical with different lenses.

The best solution would be for an experienced technician to ensure your focusing cam is adjusted to work properly with the specific lenses you own.

[Kent]

I wonder if it's really the rangefinder as "woonder" writes that he's fine with three of his lenses. If the RF is misaligned, wouldn't that mean that all of those well working lenses are exactly misaligned in the same way and the same degree? How likely is that?

My M8 works perfectly with my Heliar 15, my Ultron 28, my Summitar 50, my Heliar 75 and even with my Elmar 90. Gosh, I can even use my Hektor 135 on that M8 and get sharp pictures. But an Ultron 35 I recently tried was impossible to focus properly.
A short test on my NEX-7 (with live view and peaking) showed that the Ultron 35 had a problem.

Anyway, a decent check by a qualified technician is worth it.

[jsrockit]

The 40mm CV definitely shifts...