CV 35mm PII focus problem

[Dunn]

I just bought a used CV 35mm PII from eBay. The lens looks brand new in every aspect, but when I tried focusing on an object that would clearly be at infinity it isn't in focus. I actually have to nudge the focus just a tad back from infinity for the object to be in focus. I verified that my rangefinder is okay by focusing on the same object with my 50mm summicron and it is in perfect focus.

What's the problem with the PII? Is it a big problem? My big concern is when I'll be shooting wide open and focusing on something specific.

Would you recommend returning to seller or try to get it repaired, if it isn't too much?

Thanks.

 

[Turtle]

But when you focus on items are they in focus i.e. if you focus on infinity with the rangefinder is it accurate?

Mine did this and seeing as I never use the inifinty stop for anything, I kept it bec it performed so incredibly well in every other regard. Seems like the focus ring is not correctly aligned but the cam lines up for correct focus. Weird, but I have heard of this from others. Mine is just a hair out of inifinity in that you can focus just past infinity.

I should add that mine focused smack on from close up and wide open to any other distance so it was a non issue for me.

 

[ferider]

That is a typical problem: the lens is in spec, the camera as well, but the combo isn't. Usually, because the camera's RF roller is not completely parallel to the film plane, and one lens hits it "just right", the other one is a bit off since hitting the camera roller lower or higher.

As a rule of thumb, multiply your focal lenth by thousand. If the focusing error is between this (in your case 35 meter) and infinity, you'll be OK.

If you do want to adjust the PII to the camera perfectly, you can do so if you have a lens spanner and a screw driver. (1) take off the rear span ring, (2) take the optical block out of the focus helix. In the focus mount, from the front, you will see screws that you can (3) loosen, fine adjust the focusing, and then tighten again. Last (4) apply some nail polish on those screws after tightening.

Here you see those adjustment screws with the 35/1.4 Nokton. The PII is very similar:

Note that this kind of adjustment can only be done with your camera in hands - sending the lens for repair without camera will not help, the lens will actually work correctly on some other bodies.

Hope this helps,

Roland.

 

[mtargz]

FWIW, my 35 PanII does the same - slightly off at the marked infinity stop. I'm guessing the markings themselves are simply misaligned, because at all distances, a lined-up rangefinder image (Hexar RF) results in a sharp picture. Even wide-open at minimum focus, the sharpest plane is the one I focused on - and it's the close focus that counts more than infinity, which is easy to estimate if need be.

In short, I wouldn't worry about it, but it does raise an eyebrow regarding the QC on that thing.

 

[ferider]

It has nothing to do with Cosina/Voigtlander QC. The lens is fine.

 

[Dunn]

Okay, cool.

So, what you're saying is that then lens is fine and just doesn't line up with the camera. But does that mean that I should worry about any mis-focusing? Or does the focus ring just go a little too far? I seriously BARELY have to move it back from infinity to have the "proper" focus.

Should I just use it as I normally would and ignore when I focus at infinity?

 

[ferider]

Just use it and see if the results are good.

Also, when you shoot the lens at infinity, just put it at infinity and don't worry about the small misalignment. This will give you the best performance.

Roland.

 

[Turtle]

Do a test. I noticed this issue after doing a focus test in which it performed perfectly. I freaked out, retested, and found out that focus was indeed perfectly fine at all distances. Now I ignore it.