Sigma 150-500 on a K20D?

I'm looking for a lens for wildlife and flying aircraft pictures, and this one seems to fit the bill. There seems however, to be some doubt as to whether it will be fully functional when used with a Pentax body.

Has anyone got any experience using this lens? Do you get full high speed autofocus and optical stabilisation?

Is the final product likely to be better than a crop of a picture taken with a DA*300 prime?

Thanks in advance

The lens is out and available in the Pentax mount. The only difference between the Pentax model and other mounts is that it doesn't have Sigmas OS (optical stabilisation) as you already have that in the latest Pentax DSLRs. You will need a model of Pentax that uses SDM (e.g. K20D K10D) for auto-focus to work as the lens only uses SDM/HSM and has no AF screw.

There was a recent comparison over at either dpreview.com or pentaxforums.com that compared the old Sigma 50-500mm, 170-500mm and this new 150-500mm. The conclusion seems to be that the 170-500mm is the worst of the bunch and the 50-500mm and 170-500mm are on a par with each other.

I'm presuming you meant 50-500mm and 150-500mm are on a par with each other?

You may find this thread on DPR useful as it compares the 150-500, 50-500, 170-500 and the Pentax A*300 + 1.7AF TC http://forums.dpreview.com/forums/read.asp?forum=1036&message=30516501

I did mean that, thanks

Thanks for the replies. That review made interesting reading/viewing.

At the moment the 150-500 looks probable. The optical performance looks similar, but as far as I can work out, the Bigma does not have HSM in Pentax fit

Another thought went through my mind - it's easier to "find" a fast moving aircraft with a zoom than a prime (unless there is a technique for the latter)

With the price of the DA* going exponential, I think I know what my Xmas bonus is going on.

Cheers for the help.

Yup - I was right.

Courtesy of the nice people at SRS Microsystems (ordered on the www monday night, knock at the door this morning).

The focus action is a revelation, and from the little I've used it the lens seems very good, but one quirk I have noticed, if I open a photo with PhotoMe, it reports the lens as "SIGMA 70-200mm F2.8 EX DG Macro HSM II", although it does report the correct actual focal length. Any ideas?

sigma lenses are notorious for getting the reference code wrong for pentax cameras, my old sigma 28-200 is reported incorrectly when used on my K10D, just ignore it.

If it really bothers you I understand this sort of data can be edited in the image file, others may have some suggestions for such editors, I haven't done it myself (yet).

Bladerunner is correct, several Sigma lenses share the same ID in the maker notes and quite often are reported as a Pentax lens!

Sigma clone/copy the code for Pentax lenses and then apply it across several of their lenses, I suspect that all their new Pentax HSM lenses will report as the "SIGMA 70-200mm F2.8 EX DG Macro HSM II", as that was the first HSM Pentax version they released.

I agree that it's annoying.