With my K5 + DA* 16-50 I get a falling away of focus on the right side. This is not a depth of field problem, as subject detail the same distance from the lens on the left and middle of the frame is fine. Indeed, it doesn`t seem to be an issue with subjects close to the lens, but only when focus is set at, or close to, infinity. I have the autofocus set to centre, I don`t think this is the issue. Is the sensor somehow slightly out of alignment? Any thoughts welcome.

Thanks for doing that - my first time looking on here since Fri!

Hello. I try to spend as little time as possible sat on this PC, so I made it simple - for me - by just putting everything on E-Bay. Running a separate `auction` on here, with all the inquiries, and setting prices, was frankly too much hassle. So the lenses will go to the highest bidder, with no pre-set prices from me.

I am rationalising my lens collection, have just splached out on the DA 60-250. They are all currently on E-Bay until Sunday - it was just easier to do it that way! The list is :

PENTAX FA 28-105mm AL(IF) ZOOM
PENTAX SMC DA 55-300mm F4.5-5.8ED TELEZOOM
VIVITAR SERIES 1 28-105mm F2.8-3.8 ZOOM, PENTAX PK-A
TOKINA AT-X 80-200mm F2.8 TELEZOOM for PENTAX PK-A
RICOH XR RIKENON APO 300mm F4.5 TELEPHOTO for PENTAX PK

Full detail on E-Bay.

thanks Pete, I`ll give that a try.

Interesting comments on here about the Tamron SP 17-50. I bought one of these when I purchased my K20D 18 months ago, and am generally very pleased with its build and image quality. Various people have mentioned the need for AF adjustment, and I have noticed on some images (generally taken at wider than f5) that it is less than sharp on the RH side, but fine on the LH side. This suggests that I need to adjust. Can someone talk me through, in words of one syllable, how this should be done. Thanks

Excuse this slightly `soft` question, but how old is it, and I presume it`s the latest model? Guess you may have sold it now anyway.

Yes, ditto to the above re SRS. Ordered my 55-300 over the phone yesterday. Pleasant and efficient chap took my details (including Pentax Forum username for free postage). Lens arrived 09.30 this morning. I`ve printed off the cashback form, so even if it does take 4 weeks, I regard this simply as a `Brucie Bonus`!
Let`s hope the lens lives up to it`s testimonials on here!!

Well, I`ve done it now, and ordered the Pentax 55-300 from SRS - expected tomorrow. Naturally, I`m keen to see how the images compare with those taken on my old manual-focus zooms - Tokina 80-200 mm f2.8 and Ricoh 300 mm APO f4.5.

thanks for the info so far guys. It looks like the Pentax 55-300 is out in front at the mo (and the £25 cashback helps too). But image quality is more important than the price of a few more pints, so is anybody going to push the case for the Sigma 70-300 APO before I `splash the cash`? All opinions gratefully received.............