Pentax K-5 and AF Adjustment issue

I am now an enthusiastic Pentaxian, with the K-5 and the following Pentax lenses:

DA* 55 f/1.4

DA 70 f/2.4

DA 50-200 WR

DA 16-45

To achieve optimum sharpness for each of these lenses, I've had to make various in-camera AF Adjustments ranging  from -8 to +10.

(Surprisingly, I've returned a DA 15 Limited, an 18-55, and the DA 35 f/2.8 Macro Limited. With the latter,  I could not achieve tack

sharpness even after trying in both Adjustment directions, -10 and +10 (and points in between). The question is, is this "normal" for a

K-5, to need such a range of AF Adjustment for several lenses? (My 4 lenses are sharp, and the DA 70 Limited in particular is pin-

sharp! So, obviously I AM seeing superb sharpness from this camera, especially with the 70 and 55.) I'm just wondering what the

likelihood is of the DA 35 f/2.8 Macro Limited being unable to achieve the razor sharpness of the 70, on my particular camera body.

Other than this sharpness battle, I am extremely pleased with the K-5 and Pentax Quality in general!

Steve

<p>Lots of variables in testing techniques, so it's hard to say exactly where the issue might be. It does sound like more adjustment was necessary (?) than I would have expected. <br>

Regarding the DA35, I suppose that anything is possible, is it still possible to try a different copy of the lens? How well did it work with contrast-detect (live view) AF? Could you get sharp images by manually-focusing using magnified live view?</p>

Valid points, Amdrew! Actually, it so happens that I was rather time-constrained when ai made my first round of

testing, and didn't try another DA 35 Ltd, which could very well have been fine. I used the default Live View focus

method, and frankly, am either too blind or lazy to rely on anything but Auto Focus! My whole dilemma is wondering if

this AF Adjustment is just par for the course with modern DSLRs that have the facility, OR, do I just have a particular

K-5 body that is a bit "out" more in one direction, and thus require more adjustment with certain lenses!

<p>Only Pentax knows the in-built tolerances for AF adjustment (or lack of). With my lenses, I can not perceive any needs to adjust the AF. I have the 15 Ltd and 35 macro Ltd. And I have the 100 macro WR on the way.</p>

<p>My K-7 had this issue following shutter replacement. Prior to it my adjustments were sub +/- 5 with all but on lens I own, subsequent to the repair I was at 10 and still out of range with some lenses.</p>

<p>I would send the K-5 in for servicing. I'd have sent it in with the worst current lens (the DA 35 or DA 15 both sound like you couldn't get them adjusted). BTW, the DA 15 is tough to adjust because wide angles are more difficult, and I suspect if your technique for adjusting isn't perfect you will see a lot of variability. On the flip side, the DA 70 is much easier to adjust.</p>

<p>When I sent mine in, I noted it was failing to adjust on many current DA Limited lenses, as well as current production FA Limited, and discontinued FA lenses. I noted that while I understood potential for it not calibrating with legacy lenses or 3rd party lenses, there was clearly an issue when a current production lens didn't work. I sent my 21mm DA in with it to prove the point.</p>

<p>Regardless, -/+ 8 is getting to the edge of the range, I really would be concerned that your AF system isn't properly calibrated out of the factory.</p>