K10D focus problem... (again)

Nuutti · 06-25-2008, 03:38 PM

I've long been wondering why a huge amount of my pictures are off-focus. I thought I'm doing something wrong when focusing (focus spot off-target, AF finding something that I've not noticed etc). After I found this forum couple of days ago I realized that maybe my K10D is back-focusing.

I took couple of test pictures. These are center crops - the original ones includes the whole paper. First with
Sigma 100-300 mm f/4 which I just bought. This one is - I think - just perfect.

The next one is taken with Pentax DA* 50-135 mm f/2.8 which I've mainly been using. I think the focus is 20-30 mm too far. I took several pictures with this lens and this is the best one. How this will affect focusing when the distance is e.g. 20 meters or something?

Focus was OK also with Pentax DA 16-45 mm f/4.

Is there any cure for this? For just this Pentax DA* 50-135 mm lens so that nothing would change with other lenses?

pentkon52 · 06-25-2008, 04:33 PM

Well for one thing, your not square to the target, and it looks like your shooting at a pretty high angle.

The sigma looks off atad as well ,but not much.

Test it in field conditions as well.

Some members of the PDML have noticed some focus issues with the DA * lenses on earlier model K10D;s.

I suggest sending the camera and lenses in to Pentax to look at.
That was how i solved my problem. Sending in the lenses so they could set up the camera.

Dave

flyer · 06-25-2008, 04:38 PM

Before sending anything to Pentax, the test should be re-done with the camera level, square with the target and thee target at a 45 deg. angle. Right now, it just shows sloppiness where EVERYTHING should be done to control the shoot and avoid variables that could influence the results.