[murgur]

I will buy a dslr for fotographing birds, my Canon S2 is no longer enough for me. K10D seems to be the best cost effective choice, but there is an important problem: Sigma does not produce HSM lenses for Pentax yet. If you buy Sigma 50-500, you will have to use it without HSM. Focusing speed is very important for bird photos, so is the HSM feature.
Does Pentax plan to produce telephoto lenses with ultrasonic motors? I cannot wait for a year, if they will not, I will have to prefer a Canon or Nikon camera.

[GaryML]

Does Pentax plan to produce telephoto lenses with ultrasonic motors?

The Pentax Lens Roadmap lists a DA* 300mm f4 lens with in-lens motor ("SDM") to be available after September 2007, and a DA*60-250mm f4 SDM zoom to be available after December 2007. Those are the longest lenses currently listed on the Roadmap. Here's the link to the Roadmap .pdf file (in English):

http://www.digital.pentax.co.jp/en/lens/roadmap.pdf

For a lens longer than 300mm, the only options in current product are the Sigma lenses (135-400mm, 170-500mm and 50-500mm). And, as you noted, they use the in-body focus rather than SDM or HSM. Future support for SDM/HSM by Sigma is unknown at present. I have a Sigma 100-300mm f4 EX DG lens, and the focus speed with the in-body motor is sufficient for my needs. You may want to try the Sigma 50-500 with a K10D body; you might find that the auto-focus is adequate for your needs.

I like my Pentax equipment and it gets the job done for me, but in all honesty it may not be the best choice for serious bird photography. Canon and Nikon have many more options for lenses in the 400mm+ range. But be prepared for expensive, bulky and heavy equipment!

[Skorzen]

as the previous reply mentioned pentax does have some lenses with in lens motors on the way, but as we have seen with the 16-50 and 50-135 with in lens motors being pushed back I would not necessary count on the dates we have been given. I don't mean to talk bad about pentax I love my camera but I think to be realistic I would not bet my life that I will be able to pickup a DA* 300 in September.

[GaryML]

as the previous reply mentioned pentax does have some lenses with in lens motors on the way, but as we have seen with the 16-50 and 50-135 with in lens motors being pushed back I would not necessary count on the dates we have been given. I don't mean to talk bad about pentax I love my camera but I think to be realistic I would not bet my life that I will be able to pickup a DA* 300 in September.

I agree completely. That's why I stated after the projected release dates. Perhaps up to three months after the projected dates.

[murgur]

Thank you very much. I think Pentax should cooperate with Sigma, to make Sigma produce the HSM lenses for Pentax as soon as possible.

[jnorth]

Thank you very much. I think Pentax should cooperate with Sigma, to make Sigma produce the HSM lenses for Pentax as soon as possible.

Great idea but if Pentax can't even get their own lenses out the door fast enough how are they going to demand Sigma do it any faster. The 3rd parties are likely all waiting to see what Pentax themselves do with the lenses, before they commit their resources to developing something from scratch, and considering they will only be supported with the K10D, and only after Pentax releases a firmware update, it just seems a bit to pie in the sky this week. But it sure would be nice to see some Pentax, and 3rd party options soon.