Front focusing on K20D

Hi
I have identified that my k20d front focuses quite significantly. Since I got it, I could not understand why sharpness is poorer than on my k100d. Finally, yesterday I read about front/back focusing issue, I tested it at home, corrected and now looks fine. However, my concern is that I did the test on 55mm and aperture of 2.8 for one lens only. Will it now work fine for all other focal length and other lenses?

Other question is, is this focusing problem a cameras fault or lens fault?

Thanks

If it's a Pentax lens, the camera will remember that lens (and up to 19 more) and apply the correction whenever it is fitted, assuming you made an individual correction and not a global one.

global at the moment. Still want to test it for different focal length just to be sure. What you are saying is that it will not remember third party lenses?

It may remember third party lenses, but as they sometimes mis-report I wouldn't be at all surprised if some of them cause a problem. Nobody seems to have mentioned it as an issue yet, so it's just a theory.

A global adjustment will apply to all lenses, so may well not be appropriate.

until yesterday I wasn't aware of the fact that a camera can have such focusing problems. That basically means that each and every lens should be first tested for focusing just to be sure? Is this a Pentax specific problem or Canons Nikons and others have the same?

Thank you

It's the same for all makes and incresingly manufacturers are providing the means to make fine adjustments.

I wouldn't get too anxious about it though - I have owned a lot of lenses and none so far have needed any adjustment.

Yes it will remember any lens that has an ID chip inside it. Some Signma lenses publish the same ID though. My Sigma 30/1.4 and Sigma 135-400 do which means the the camera ant distinguish between them for AF adjustment.

Fortuntely on one of my K-5s the AF adjustment was the same at +5, but on the other K-5 it was 0 and +9 respectively. So to get around this I set the second K-5 to +9 for these lenses and only use the 135-400 on it.


I've owned a K10D, K20 and two K-5s and most of my several lenses have required some AF adjustment.

It's no biggie though and a simple process to spend a few minutes calibrating them