[Jewelltrail]

I have a question concerning this lens. At this link:

SIGMA 10-20mm F4-5.6 EX DC AF Lens For Pentax if you click on the tab for product description, there is a bullet followed by these words: "Equipped with HSM (Hyper Sonic Motor) system ." Now, I know the newer, f 3.5 10-20 will have HSM, but is there also a "new" version of the f4 5.6 which allows use of HSM on Pentax mount too?

I would appreciate any help--thanks.

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Last edited by Jewelltrail; 05-22-2009 at 09:33 PM. Reason: accuracy

[jem]

According to Sigma no - only Nikon, Canon & Sigma versions. Looks like Abe's did a standard copy/paste without all the additional details.

[Jewelltrail]

jem According to Sigma no - only Nikon, Canon & Sigma versions. Looks like Abe's did a standard copy/paste without all the additional details.

I would say you are correct; we must assume Sigma knows its lenses better than Abes does--even if Abes is an "Authorized Sigma Dealer." Not to knock Abes, they are a good outfit.

[philbaum]

jeweltrail,

My older 10-20 definitely does not have HSM.

Mybe others have comments about this, but my Sigma 10-20 (presently on loan to a brother so i can't check it out) never seemed to take very long to focus. A short buzz and its there. I think this is an aspect of ultra wide lenses. Another thing, on the 10mm FL, i did have occasions inside where the lens had difficulty accurately focusing. But at 10, even with my split focusing screen, it was hard to tell the difference between in focus and out of focus, if that makes any sense. So i would just dial up an estimated distance on the focus ring and that always worked. As 12mm FL and on up, the auto focus worked just fine, it was at the 10/11 area where the camera had difficulty.

best wishes on your hunt,

[jem]

I would say you are correct; we must assume Sigma knows its lenses better than Abes does--even if Abes is an "Authorized Sigma Dealer." Not to knock Abes, they are a good outfit.

Yes, agreed on Abe's - bought from them before - always went well.

By the way, I usually go to Sigma's Japan site for the definative word on their lenses. Even Sigma USA sometime munges or leaves out info on their lenses. The Japan site is where I discovered that my brand new Sigma 1.4 Teleconverter really isn't compatible with my new Sigma 150-500mm HSM even in manual mode. Whereas the USA site uses the generalization 'it works' with our teleconverters. Argh!

[MoiVous]

jeweltrail,

My older 10-20 definitely does not have HSM.

Mybe others have comments about this, but my Sigma 10-20 (presently on loan to a brother so i can't check it out) never seemed to take very long to focus. A short buzz and its there. I think this is an aspect of ultra wide lenses. Another thing, on the 10mm FL, i did have occasions inside where the lens had difficulty accurately focusing. But at 10, even with my split focusing screen, it was hard to tell the difference between in focus and out of focus, if that makes any sense. So i would just dial up an estimated distance on the focus ring and that always worked. As 12mm FL and on up, the auto focus worked just fine, it was at the 10/11 area where the camera had difficulty.

best wishes on your hunt,

I'm glad to hear that its a bit off at 10mm - I was worried my Sigma 10-20 was a bit off. The AF at 10mm seems to be quite poor. I've taken to switching AF OFF then setting the focus to about 1m or more and shooting (I've taken to using f8 to f11 as well). Seems to give more consistent results.

I've read lots on this forum about the Sigma 10-20mm and have been worried about the lens being soft (all those stories of bad copies), but after switching to manual at 10mm, I'm happier. Does anyone have a lens test method to double check this at each focal length?

I had a look at Bob Atkins page on lens testing and it seems like the simplest method. Any other suggestions?

Cheers