Pentax D-100 lens help

divine_kyrie · 08-19-2011, 05:13 PM

I just recently purchased this lens after much research. It's supposed to be compatible with my camera, however I'm having an issue. The lens fits perfectly, clicks in place, manual focus works beautifully, the autofocus does not work. This is actually the second lens I got from B & H because when I got the first one it did this too and I thought it was defective. Now I'm wondering if they are not compatible or if I'm doing something wrong. Please help!

Sigma 18-50mm f/2.8-4.5 DC OS HSM Zoom For Pentax 861109 B&H

Adam · 08-19-2011, 05:21 PM

The K100D doesn't support SDM (HSM on Sigma lenses) autofocus. You'll want to upgrade to a K100D super, or to a K-r (that would probably be easiest).

divine_kyrie · 08-19-2011, 06:35 PM

So is there nothing I can do to make this work? I was really looking forward to a lens with lower aperture.

**Ash** · 08-19-2011, 06:47 PM

Unfortunately not. The screwdrive autofocus mechanism is not buit into the Sigma HSM lens, so it will not work on your current camera. Good reason to upgrade your camera to a K-x or K-r.

divine_kyrie · 08-19-2011, 06:51 PM

Bummer! Can anyone recommend a lens that would be compatible with lower aperture, zoom, and autofocus?

SpecialK · 08-19-2011, 07:29 PM

Any of the DA type of Pentax lenses, and a lot of other brands make compatible lens - just avoid "SDM" and "HSM" and other lenses with reference to a silent focusing motor.

You can check out the Lens Database in the "Lenses" link at the top of this page.

You might find an older Sigma 17-70 or Sigma 18-50 in the Marketplace, or make a Wanted post.

tibbitts · 08-24-2011, 07:40 PM

I think the Tamron 17-50mm for Pentax has screw drive, but I'm not sure. Many people here own that lens and I'm sure they'll reply.

Paul

divine_kyrie · 08-26-2011, 07:20 AM

Thanks! Is this the lens you were talking about? Does anyone know if it is compatible??? Oh and I'm not sure why I wrote D-100 when my camera is a k100.

Tamron 17-50mm f/2.8 XR Di-II LD Aspherical [IF] AF016P-700 B&H

tibbitts · 08-26-2011, 08:18 PM

Sorry, I have a K100 but not that lens. If you can't find the info with a search, post a question in the lens forum and someone can confirm/deny if it has screw drive. That is the lens I was thinking of.

Paul

08-19-2011, 05:13 PM	#1
divine_kyrie New Member Join Date: Aug 2011 Location: Idaho Posts: 4	Pentax D-100 lens help I just recently purchased this lens after much research. It's supposed to be compatible with my camera, however I'm having an issue. The lens fits perfectly, clicks in place, manual focus works beautifully, the autofocus does not work. This is actually the second lens I got from B & H because when I got the first one it did this too and I thought it was defective. Now I'm wondering if they are not compatible or if I'm doing something wrong. Please help! Sigma 18-50mm f/2.8-4.5 DC OS HSM Zoom For Pentax 861109 B&H

08-19-2011, 05:21 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	The K100D doesn't support SDM (HSM on Sigma lenses) autofocus. You'll want to upgrade to a K100D super, or to a K-r (that would probably be easiest). Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

08-19-2011, 07:29 PM	#6
SpecialK Pentaxian Join Date: Dec 2006 Location: So California Photos: Gallery Posts: 16,482	Any of the DA type of Pentax lenses, and a lot of other brands make compatible lens - just avoid "SDM" and "HSM" and other lenses with reference to a silent focusing motor. You can check out the Lens Database in the "Lenses" link at the top of this page. You might find an older Sigma 17-70 or Sigma 18-50 in the Marketplace, or make a Wanted post. Last edited by SpecialK; 08-19-2011 at 07:35 PM.

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08-19-2011, 06:35 PM	#3
divine_kyrie New Member Join Date: Aug 2011 Location: Idaho Posts: 4 Original Poster	So is there nothing I can do to make this work? I was really looking forward to a lens with lower aperture.

08-19-2011, 06:47 PM	#4
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Unfortunately not. The screwdrive autofocus mechanism is not buit into the Sigma HSM lens, so it will not work on your current camera. Good reason to upgrade your camera to a K-x or K-r.

08-19-2011, 06:51 PM	#5
divine_kyrie New Member Join Date: Aug 2011 Location: Idaho Posts: 4 Original Poster	Bummer! Can anyone recommend a lens that would be compatible with lower aperture, zoom, and autofocus?

08-24-2011, 07:40 PM	#7
tibbitts Pentaxian Join Date: Apr 2007 Location: Oklahoma USA Posts: 2,196	I think the Tamron 17-50mm for Pentax has screw drive, but I'm not sure. Many people here own that lens and I'm sure they'll reply. Paul

08-26-2011, 07:20 AM	#8
divine_kyrie New Member Join Date: Aug 2011 Location: Idaho Posts: 4 Original Poster	Thanks! Is this the lens you were talking about? Does anyone know if it is compatible??? Oh and I'm not sure why I wrote D-100 when my camera is a k100. Tamron 17-50mm f/2.8 XR Di-II LD Aspherical [IF] AF016P-700 B&H

08-26-2011, 08:18 PM	#9
tibbitts Pentaxian Join Date: Apr 2007 Location: Oklahoma USA Posts: 2,196	Sorry, I have a K100 but not that lens. If you can't find the info with a search, post a question in the lens forum and someone can confirm/deny if it has screw drive. That is the lens I was thinking of. Paul