Do Any TC's Work With Pentax SDM Lenses?

Christopher M.W.T · 09-25-2009, 01:44 AM

As the title says.

I'm getting a DA50-135 and just wondering if there is a TC that will allow full use of SDM?

axl · 09-25-2009, 01:49 AM

some of the Kenko 1.5x apparently do, you just need to check if the power zoom contacts are there and not blinded. And i think the story with Kenko 2x MC7 is the same. I think the new ones won't work as the contacts are shorted

BR
Peter

netuser · 09-25-2009, 01:54 AM

Kenko 1.5x with powerzoom contacts works, Kenko 2x MC7 with power zoom contacts it doesn´t, only manual focus.
Also tamron 1.4x with power zoom contacts works.

bymy141 · 09-25-2009, 03:24 AM

Originally posted by netuser

Kenko 1.5x with powerzoom contacts works, Kenko 2x MC7 with power zoom contacts it doesn´t, only manual focus.
Also tamron 1.4x with power zoom contacts works.

Yes, my Kenko 1.5 TC works fine, BUT! the camera does not understand that there is a TC between the lens and camera. So, all information, like: focal length (important voor the SR algoritm), diafragma etc. are not altered to the real values.

- Bert

Christopher M.W.T · 09-25-2009, 03:29 AM

How much do they degrade IQ though?

netuser · 09-25-2009, 05:25 AM

Originally posted by C.W Tsorotes

How much do they degrade IQ though?

Almost none with Tamron 1.4x

Oggy · 09-25-2009, 03:34 PM

Originally posted by C.W Tsorotes

As the title says.

I'm getting a DA50-135 and just wondering if there is a TC that will allow full use of SDM?

I have the Tamron 1.4xPz AF MC4.

I does work with SDM lenses in that sooner or later it will give focus confirm and take a picture.

As to image quality, I'd have to differ with Netuser. The 50-135 is one of the best lenses Pentax make and it's a bit like buying a Ferrari and putting Kumho economy tyres on it.

SOldBear · 09-25-2009, 05:11 PM

Originally posted by netuser

Also tamron 1.4x with power zoom contacts works.

Did you actually try it yourself?

My Tamron 1.4X TC does not work with my DA* 50-135mm. The lens will hunt back and forth for a few seconds on half-press of the shutter release. Then if I remove my finger and then half-press again, it will focus.

I wouldn't call that "working."

My 1.7X Pentax AFA sure works, but it works with anything

snostorm · 09-26-2009, 12:49 PM

Originally posted by SOldBear

My Tamron 1.4X TC does not work with my DA* 50-135mm. The lens will hunt back and forth for a few seconds on half-press of the shutter release. Then if I remove my finger and then half-press again, it will focus.

I wouldn't call that "working."

My 1.7X Pentax AFA sure works, but it works with anything

Hi SOldBear,

My experience exactly matches yours . . . with both TCs. I unfortunately don't think that any definitive statement can be made about which TC will work with SDM -- except for the 1.7x AFA.

Scott

09-25-2009, 01:44 AM	#1
Christopher M.W.T Veteran Member Join Date: Jun 2009 Posts: 1,689	Do Any TC's Work With Pentax SDM Lenses? As the title says. I'm getting a DA50-135 and just wondering if there is a TC that will allow full use of SDM?

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09-25-2009, 01:49 AM	#2
axl Veteran Member Join Date: Mar 2007 Location: Nove Zamky, Slovakia Photos: Gallery \| Albums Posts: 7,183	some of the Kenko 1.5x apparently do, you just need to check if the power zoom contacts are there and not blinded. And i think the story with Kenko 2x MC7 is the same. I think the new ones won't work as the contacts are shorted BR Peter

09-25-2009, 01:54 AM	#3
netuser Veteran Member Join Date: Oct 2008 Location: Azores Islands, Portugal Photos: Gallery Posts: 2,236	Kenko 1.5x with powerzoom contacts works, Kenko 2x MC7 with power zoom contacts it doesn´t, only manual focus. Also tamron 1.4x with power zoom contacts works.

09-25-2009, 03:24 AM	#4
bymy141 Veteran Member Join Date: Aug 2007 Photos: Gallery Posts: 1,563	Originally posted by netuser Kenko 1.5x with powerzoom contacts works, Kenko 2x MC7 with power zoom contacts it doesn´t, only manual focus. Also tamron 1.4x with power zoom contacts works. Yes, my Kenko 1.5 TC works fine, BUT! the camera does not understand that there is a TC between the lens and camera. So, all information, like: focal length (important voor the SR algoritm), diafragma etc. are not altered to the real values. - Bert

09-25-2009, 03:29 AM	#5
Christopher M.W.T Veteran Member Join Date: Jun 2009 Posts: 1,689 Original Poster	How much do they degrade IQ though?

09-25-2009, 05:25 AM	#6
netuser Veteran Member Join Date: Oct 2008 Location: Azores Islands, Portugal Photos: Gallery Posts: 2,236	Originally posted by C.W Tsorotes How much do they degrade IQ though? Almost none with Tamron 1.4x

09-25-2009, 03:34 PM	#7
Oggy Inactive Account Join Date: Sep 2009 Location: West Sussex UK Posts: 235	Originally posted by C.W Tsorotes As the title says. I'm getting a DA50-135 and just wondering if there is a TC that will allow full use of SDM? I have the Tamron 1.4xPz AF MC4. I does work with SDM lenses in that sooner or later it will give focus confirm and take a picture. As to image quality, I'd have to differ with Netuser. The 50-135 is one of the best lenses Pentax make and it's a bit like buying a Ferrari and putting Kumho economy tyres on it.

09-25-2009, 05:11 PM	#8
SOldBear Veteran Member Join Date: Feb 2009 Location: Alameda, CA Posts: 3,206	Originally posted by netuser Also tamron 1.4x with power zoom contacts works. Did you actually try it yourself? My Tamron 1.4X TC does not work with my DA* 50-135mm. The lens will hunt back and forth for a few seconds on half-press of the shutter release. Then if I remove my finger and then half-press again, it will focus. I wouldn't call that "working." My 1.7X Pentax AFA sure works, but it works with anything

09-26-2009, 12:49 PM	#9
snostorm Veteran Member Join Date: Oct 2006 Location: Chicago suburb, IL, USA Posts: 1,535	Originally posted by SOldBear My Tamron 1.4X TC does not work with my DA* 50-135mm. The lens will hunt back and forth for a few seconds on half-press of the shutter release. Then if I remove my finger and then half-press again, it will focus. I wouldn't call that "working." My 1.7X Pentax AFA sure works, but it works with anything Hi SOldBear, My experience exactly matches yours . . . with both TCs. I unfortunately don't think that any definitive statement can be made about which TC will work with SDM -- except for the 1.7x AFA. Scott