Hi,
First, I don't know if "bad" means "front" or "back" focus problem (according to their definition, my MF lens wouldn't be case.) After many tests, I may say to myself that my combination "Kr + Super Takumar 1:1.4 50mm" has a "front-focus" problem. My lens was disassembled/assembled as you can see in this thread
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/167889-how-use...-1-4-50mm.html .
My tests are as below
Test 1:
- Mount the Super Takumar 1:1.4 50mm on the K-r
- Turn off the AF fine adjustment
- Take a picture at the maximum aperture (1:1.4)
Test 2:
- Mount the Super Takumar 1:1.4 50mm on the K-r
- Turn on the AF fine adjustment, select the value -7 (I get this value after many tests in some previous days)
- Take another picture at the aperture 1:1.4
Results: In both cases, the red signal is active to report right focus, and (the most important) I can see the clear focus from the viewfinder (I use a stock focus screen.) All images in Test 1 are *soft* (or wrong focus) (from any angle), and all images in Test 2 are sharp or very sharp as expect.
I think that my repair made something wrong to the lens (before I dissambled the lens, there's only infinity focus problem.) I'd like to know the *name* (and if possible, the cause) of this problem before moving to next fix
Please note that the problem doesn't happen with another lens (Helios 44m-4, at the maximum aperture 1:2).
Thank you for reading and helps.
Regards,