Auto Focus

royboy · 08-19-2013, 07:20 PM

I have a Pentax K10D that came fitted with a DA 1:3.5 -5.6 18 - 55 lens. About 2 years ago I purchased a DA 1:2.8 16 - 50 lens that I am very happy with. I recently purchased a Pentax K5 II and the DA 1:2.8 lens will not autofocus on this camera although DA 1:3.5 will as do some of my older Sigma lenses.
Would this be a camera or lens problem ?

VoiceOfReason · 08-19-2013, 07:41 PM

Make sure the contacts are clean on the camera, that the lens is fully seated, and make sure your battery is good.

JohnX · 08-20-2013, 12:55 AM

Could be faulty SDM.

K10D was screw-drive only prior to firmware v1.3, so if you didn't update the firmware the K10D would not support SDM and your 16-50 would've been using it's screw drive for AF.

An SDM equipped lens will always default to SDM when fitted onto a body that supports it, i.e. the K5II.

Kozlok · 08-20-2013, 12:56 PM

Some have hacked that lens to use the screwdrive on any camera. Not sure myself how to do it, but should be found on google.

VoiceOfReason · 08-20-2013, 01:12 PM

Here's the how to deactivate SDM thread: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/208353-how-dea...m-f-2-8-a.html

stevebrot · 08-20-2013, 05:14 PM

Originally posted by Kozlok

Some have hacked that lens

My understanding is that this is a firmware hack on the camera body rather than the lens that allows the two to relate as if the camera were a pre-SDM body. The lens remains SDM capable.

Steve

royboy · 08-20-2013, 05:36 PM

Originally posted by Kozlok

Some have hacked that lens to use the screwdrive on any camera. Not sure myself how to do it, but should be found on google.

Just checked the firmware on the K10D and it is version 1 so there is a possibility that the SDM has never worked. I bought this lens new about 2 and 1/2 years ago.

stevebrot · 08-20-2013, 08:29 PM

Originally posted by royboy

Just checked the firmware on the K10D and it is version 1 so there is a possibility that the SDM has never worked. I bought this lens new about 2 and 1/2 years ago.

Version 1? It is definite that your K10D never triggered that feature on the lens.

Steve

08-19-2013, 07:20 PM	#1
royboy New Member Join Date: Jul 2013 Posts: 4	Auto Focus I have a Pentax K10D that came fitted with a DA 1:3.5 -5.6 18 - 55 lens. About 2 years ago I purchased a DA 1:2.8 16 - 50 lens that I am very happy with. I recently purchased a Pentax K5 II and the DA 1:2.8 lens will not autofocus on this camera although DA 1:3.5 will as do some of my older Sigma lenses. Would this be a camera or lens problem ?

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08-19-2013, 07:41 PM	#2
VoiceOfReason Site Supporter Join Date: Jun 2010 Location: Mishawaka IN area Photos: Albums Posts: 6,124	Make sure the contacts are clean on the camera, that the lens is fully seated, and make sure your battery is good.

08-20-2013, 12:55 AM	#3
JohnX Pentaxian Join Date: Jul 2009 Location: London Posts: 1,116	Could be faulty SDM. K10D was screw-drive only prior to firmware v1.3, so if you didn't update the firmware the K10D would not support SDM and your 16-50 would've been using it's screw drive for AF. An SDM equipped lens will always default to SDM when fitted onto a body that supports it, i.e. the K5II.

08-20-2013, 12:56 PM	#4
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148	Some have hacked that lens to use the screwdrive on any camera. Not sure myself how to do it, but should be found on google.

08-20-2013, 01:12 PM	#5
VoiceOfReason Site Supporter Join Date: Jun 2010 Location: Mishawaka IN area Photos: Albums Posts: 6,124	Here's the how to deactivate SDM thread: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/208353-how-dea...m-f-2-8-a.html

08-20-2013, 05:14 PM	#6
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Kozlok Some have hacked that lens My understanding is that this is a firmware hack on the camera body rather than the lens that allows the two to relate as if the camera were a pre-SDM body. The lens remains SDM capable. Steve

08-20-2013, 05:36 PM	#7
royboy New Member Join Date: Jul 2013 Posts: 4 Original Poster	Originally posted by Kozlok Some have hacked that lens to use the screwdrive on any camera. Not sure myself how to do it, but should be found on google. Just checked the firmware on the K10D and it is version 1 so there is a possibility that the SDM has never worked. I bought this lens new about 2 and 1/2 years ago.

08-20-2013, 08:29 PM	#8
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by royboy Just checked the firmware on the K10D and it is version 1 so there is a possibility that the SDM has never worked. I bought this lens new about 2 and 1/2 years ago. Version 1? It is definite that your K10D never triggered that feature on the lens. Steve