[KerryMcClain]

I've run into an issue & wanted to post here to see what you guys think. I just bought a used 15mm Limited and am getting inaccurate AF on my K5. I went through my normal test/adjust routine, with which I've successfully dialed in other lenses. The problem with this 15 is, I'm maxed out at +10 and it's still significantly back focused. Is this something that Pentax can fix if I send it in for service?

Thanks,
Kerry
kerry mcclain photography

[yusuf]

Can you post pics please

[wlachan]

That means the AF sensor of your camera sits farther back than the software can compensate. The reason it only has problem with the DA15 is that the glass travel is much smaller as the focal length decreases (just observe how the rear of the lens moves as you rotate the focus ring). The service centre surely can fix that. They will either hook the camera to computer and input the amount of compensate required for that lens, or they will readjust the AF sensor, or both. But before doing so, you might wish to retest with normal targets a few meters away instead of relying on printed chart totally.

[KerryMcClain]

Thanks for the input. Actually, I don't use printed charts for focus testing & have put this lens through extensive testing in multiple scenarios. I wasn't wondering *if* the issue exists, just wondering if the lens could be brought back into spec...but, what you say about the AF sensor in the camera makes sense. I've had a couple of other lenses that required +8 adjustment with this body to be spot on. Seems that I'm seeing a pattern of needing adjustments to the high end of the + side, and the camera is the common component. That may well be where the issue is. Thanks again!