Best Adapter for CZJena 180 Sonnar f2.8?

[Jim Schemel]

Just purchased a nice copy of the CZJena 180mm f2.8 Sonnar with adapter for EOS it seems that the lens is soft wide open but better when stopped down to f4 when doing some tests it seems that it could be sharper even wide open but is not able to focus on the subject but wants to back focus just a bit(a foot or two behind the subject is sharper than the object intended to be in focus) I think that it could be the adapter.Am i thinking right or is it possibly the lens that is out of calibration.Any suggestions on this would be greatly appreciated.Is there more than one type of adapter for this lens for Canon EOS? I can post samples if needed.
-Jim

[no-X]

Manual lens nor adapter can't suffer from back/front-focus issue - the lens doesn't take two images - one for focusign screen and another for digital sensor. It's still one/ the same image, which is used for focusing screen and camera sensor. The cause of this problem is in missaligned focusing screen or sensor. They should be in the same distance from the lens, but if one of them is closer than the other, problem is arised. Your DSLR simply needs adjustment.

[Jim Schemel]

no-X ,
I really appreciate your input.So What would you suggest first, how would i adjust focusing screen?.I never had this problem show up with my other MF lenses.I really believe that this lens can be sharp wide open if i get everything adjusted right.
Thanks
-Jim

[no-X]

Have you ever used a MF lens of this focal focal length (or any other fast lens >200mm)? The problem should be perceptible when using any MF lens. But shorter focal lenght can lead in lesser front/back-focus error.

Try to download any front/back focus test chart (e.g. this one), print it, lay it somewhere and try to take some pictures by your Sonnar (and by other MF lens for comparision) wide opened. Take the picture of the chart under angle of 45°, focus on the central line (to get images like this one) and then check the photos, if you are really consistently getting sharp image in front (or behind) the line.

If you get the same (front focus or back focus) error on all photos, than your camera definitely needs adjustment (I'd recommend service). If you sometimes get front-focus and other time back-focus, than you just didn't focus properly and the camera is fine

[Jim Schemel]

no-X,
again thanks for taking the time to respond.You asked the right question.This is my first MF lens in this focal length all others were 135 and under. I have the focus charts and i will run a test first chance i get.If i have to send it in to Canon, what would i ask them to adjust?

[Jim Schemel]

In doing a little more research i think that i will order the focus screen washers from canon so i can make sure that my screen is properly adjusted.I will let all know how it goes.
-Jim