18-135mm WR on K100D

TropicalMonkey · 01-26-2013, 07:18 PM

Auto focusing of 18-135mm WR does not work on K100D.
I was under the impression that all Pentax Lenses are compatible with all their cameras.
What is the difference of 18-135mm WR compared to 18-55mm AL?

Thanks!

Adam · 01-26-2013, 07:23 PM

Originally posted by TropicalMonkey

Auto focusing of 18-135mm WR does not work on K100D.
I was under the impression that all Pentax Lenses are compatible with all their cameras.
What is the difference of 18-135mm WR compared to 18-55mm AL?

Thanks!

The 18-55mm relies on the traditional in-camera AF motor, which is found in every Pentax DSLR.

The 18-135mm has silent SDM (aka DC) in-lens autofocus which is supported by the K100D Super and newer. You can still use the lens on your K100D, but it's not going to AF because your camera lacks the hardware to power the lens's motor.

TropicalMonkey · 01-26-2013, 07:32 PM

Thanks!
I did not realize that it is SDM. I read about SDM internal motor but did not realize that 18-135 WR is an SDM lens.

Adam · 01-26-2013, 07:50 PM

Originally posted by TropicalMonkey

Thanks!
I did not realize that it is SDM. I read about SDM internal motor but did not realize that 18-135 WR is an SDM lens.

They brand it as "DC" because it uses a different technology than other SDM lenses (notice how the focusing ring is behind the zoom ring, unlike on other Pentax lenses). That's why it focuses so much faster than other SDM lenses. Plus, ironically, it doesn't break down.

Adam
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**klh** · 01-26-2013, 08:02 PM

Sounds like an excuse for a new camera!

Giklab · 01-26-2013, 11:54 PM

This ^

.

MegaPower · 01-27-2013, 07:39 AM

18-135 use a ring type motor, called DC motor by Pentax.
It is silence, fast and accurate.
I like the DC more than the SDM, but dislike the 18-135 for not having a distance scale.

TropicalMonkey · 01-27-2013, 07:53 AM

Originally posted by klh

Sounds like an excuse for a new camera!

I just got my new K5 and this lens came with it ;-)

01-26-2013, 07:18 PM	#1
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304	18-135mm WR on K100D Auto focusing of 18-135mm WR does not work on K100D. I was under the impression that all Pentax Lenses are compatible with all their cameras. What is the difference of 18-135mm WR compared to 18-55mm AL? Thanks!

01-26-2013, 07:23 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,597	Originally posted by TropicalMonkey Auto focusing of 18-135mm WR does not work on K100D. I was under the impression that all Pentax Lenses are compatible with all their cameras. What is the difference of 18-135mm WR compared to 18-55mm AL? Thanks! The 18-55mm relies on the traditional in-camera AF motor, which is found in every Pentax DSLR. The 18-135mm has silent SDM (aka DC) in-lens autofocus which is supported by the K100D Super and newer. You can still use the lens on your K100D, but it's not going to AF because your camera lacks the hardware to power the lens's motor. 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:

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01-26-2013, 07:32 PM	#3
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304 Original Poster	Thanks! I did not realize that it is SDM. I read about SDM internal motor but did not realize that 18-135 WR is an SDM lens.

01-26-2013, 07:50 PM	#4
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,597	Originally posted by TropicalMonkey Thanks! I did not realize that it is SDM. I read about SDM internal motor but did not realize that 18-135 WR is an SDM lens. They brand it as "DC" because it uses a different technology than other SDM lenses (notice how the focusing ring is behind the zoom ring, unlike on other Pentax lenses). That's why it focuses so much faster than other SDM lenses. Plus, ironically, it doesn't break down. 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:

01-26-2013, 08:02 PM	#5
klh Loyal Site Supporter Join Date: May 2009 Location: West Lafayette, Indiana, USA Posts: 827	Sounds like an excuse for a new camera!

01-26-2013, 11:54 PM	#6
Giklab Veteran Member Join Date: Jan 2012 Location: Slovenia Photos: Gallery Posts: 2,182	This ^ .

01-27-2013, 07:39 AM	#7
MegaPower Veteran Member Join Date: May 2010 Location: Hong Kong / Irvine, CA Photos: Gallery \| Albums Posts: 636	18-135 use a ring type motor, called DC motor by Pentax. It is silence, fast and accurate. I like the DC more than the SDM, but dislike the 18-135 for not having a distance scale.

01-27-2013, 07:53 AM	#8
TropicalMonkey Veteran Member Join Date: Nov 2012 Location: Saint Paul Posts: 304 Original Poster	Originally posted by klh Sounds like an excuse for a new camera! I just got my new K5 and this lens came with it ;-)