Originally posted by pentasonic49 Hi, have you tested the focus using manual focus on the camera body
This is how I check the lens with manual focus.
1) Mount the camera on a tripod and use a focus test chart as the target.
2) Set the camera to use the back AF to focus.
3) Switch the AF/MF switch on the lens to MF
4) Set aperture to f 5.0
5) While pressing the back AF, manual focus with viewfinder until the focus confirmation shows up.
This is what I found:
6) When change the aperture to f 5.6, the focus confirmation is gone.
7) Change the aperture back to f 5.0, the focus confirmation shows up again.
Originally posted by pentasonic49 Iv'e not found any info on disabling the SDM that worked, perhaps you could enlighten me
I used an old K100D and followed the instruction from this thread:
https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/208353-how-...m-f-2-8-a.html
Hope it helps. Thanks.