Is this Pentax way of admitting SDM was a failure?

mfdesalas · 11-27-2010, 04:16 AM

I noticed the new Pentax DA 18-135 F3.5-5.6ED AL [IF] DC WR lens sports a new focusing motor, called DC, which is supposedly an improvement on SDM. I hope it proves more reliable.

Is this Pentax admitting SDM was a failure?

I struggle to understand what possessed them to wait this long to address the appalling failure rate of the SDM lenses (though of course not officially, not in the open), and I fervently hope they bring out a successor to the DA* 16-50 and 50-135 lenses soon.

**Ash** · 11-27-2010, 04:40 AM

Let's not be too hasty with the presumptions mate.

SDM to Pentax is no failure, but the DC motor is an overhauled improvement.
There may have been limitations to improving SDM as it was, and so needed a change of tack.
In any case, SDM was bound to be a problem given the electronics (vs the screwdrive's mechanics) that are more prone to kicking the bucket. Whether there are higher failure rates with SDM as opposed to HSM or USM, who really knows, but each have their failings, whereas screwdriven lenses don't.

So is Pentax admitting SDM was a flop - nope, they've been flat out denying that to date. And I'm not convinced it is myself (well maybe a little...), on the overall scheme of things, even though I know there are many stories of SDM motor failures.

blende8 · 11-27-2010, 04:44 AM

It is clear that they will not admit this openly.
But it is clear that SDM was a failure.
It is very slow and the fault rate is too high.

I doubt that we will ever see another, new SDM lens.

Only time will tell, if the new motor is any better.

Mike Cash · 11-27-2010, 04:50 AM

Hard to beat finger-drive for reliability.

**Ash** · 11-27-2010, 04:58 AM

Originally posted by Mike Cash

Hard to beat finger-drive for reliability.

Not being cynical are you Mike?
That's unlike you.

Well, maybe you're right, and the reason why Pentax made quick shift...

cameraboy · 11-27-2010, 05:06 AM

hi pentaxians, i have the 55f1.4 & as usual to be rebuffed how much speed do most people need to take a snap. loved the k5 review read it while in penang just got back & read the 18-135 review delicious cant wait sorry i kn ow its the wrong place every time to post my sentiments but i am so exited waiting to get the money together for ak5 & a18-135 thanks ian

jolepp · 11-27-2010, 05:13 AM

This could be seen as an implicit admission of failure as it includes abadoning an acronym; if something is successfull and highly regarded (e.g. "SMC") the term for it tends to stick and marketing is about <term> having been improved, <new term> implies replacing something (where the techincal reality and what is implied in marketing lingo don't always meet ;-)

cameraboy · 11-27-2010, 05:21 AM

sorry my friend but pentax has never been a failure just slow on the uptake look back in pentax history the first metering camera ETC ETC ETC.

sterretje · 11-27-2010, 05:21 AM

I've read on the web (interview with Ned ... I think it was) that the DC is for the cheaper lenses and will not replace SDM.

I guess time will tell.

**Ash** · 11-27-2010, 05:23 AM

Originally posted by jolepp

This could be seen as an implicit admission of failure as it includes abadoning an acronym; if something is successfull and highly regarded (e.g. "SMC") the term for it tends to stick and marketing is about <term> having been improved, <new term> implies replacing something (where the techincal reality and what is implied in marketing lingo don't always meet ;-)

Or it may just be that the new technology is nothing like the old one and would be inaccurate to include the old acronym.

**Rondec** · 11-27-2010, 05:32 AM

My understanding is the DC motor is not an "improved" SDM motor at all. It is if anything a cheaper version of SDM for lower end lenses. As to whether or not it is any more reliable, no one has any idea. The first DC lenses just hit the market last week -- a little soon to say it is any better than SDM.

By all accounts, it is no faster than SDM. The focus throw on the 18-135 is shorter and so it gets places faster, but that is true as well for the DA 17-70 which uses SDM technology and is a pretty fast focuser.

Mike Cash · 11-27-2010, 05:42 AM

Originally posted by cameraboy

look back in pentax history the first metering camera ETC ETC ETC.

Before Kodak did it in 1938?

Originally posted by Ash

Well, maybe you're right, and the reason why Pentax made quick shift...

If doing it with your fingers is quick shift.....then is allowing the camera to do it slow shift?

omega leader · 11-27-2010, 07:26 AM

Originally posted by Rondec

By all accounts, it is no faster than SDM. The focus throw on the 18-135 is shorter and so it gets places faster, but that is true as well for the DA 17-70 which uses SDM technology and is a pretty fast focuser.

From what I've heard this isn't true. The throw on the 18-135mm is apparently 120deg which is long enough for an autofocus lens.

Adam posted the review here and it looks good.

kenyee · 11-27-2010, 07:37 AM

Originally posted by sterretje

I've read on the web (interview with Ned ... I think it was) that the DC is for the cheaper lenses and will not replace SDM.

ditto...afaik, DC is cheaper than SDM. Wish they'd use real ring motors for SDM...even Sigma/Tamron have added ring motor technology

Edgar_in_Indy · 11-27-2010, 07:39 AM

If they're getting rid of SDM, I say good riddance. After reading every review I could find of the Pentax 50-135mm and the Sigma 50-150mm, I've decided to go with the Sigma.

The performance/reliability issues of the SDM was the deciding factor. The Sigma seems to have comparable image quality and focuses faster. And on top of that, it has a four year warranty compared to the ridiculous 1-year warranty of the Pentax. The skimpy warranty is just too much of a gamble for an $800 lens.

11-27-2010, 04:16 AM	#1
mfdesalas New Member Join Date: Jul 2009 Location: Hobart, TAS Posts: 10	Is this Pentax way of admitting SDM was a failure? I noticed the new Pentax DA 18-135 F3.5-5.6ED AL [IF] DC WR lens sports a new focusing motor, called DC, which is supposedly an improvement on SDM. I hope it proves more reliable. Is this Pentax admitting SDM was a failure? I struggle to understand what possessed them to wait this long to address the appalling failure rate of the SDM lenses (though of course not officially, not in the open), and I fervently hope they bring out a successor to the DA* 16-50 and 50-135 lenses soon.

11-27-2010, 04:40 AM	#2
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Let's not be too hasty with the presumptions mate. SDM to Pentax is no failure, but the DC motor is an overhauled improvement. There may have been limitations to improving SDM as it was, and so needed a change of tack. In any case, SDM was bound to be a problem given the electronics (vs the screwdrive's mechanics) that are more prone to kicking the bucket. Whether there are higher failure rates with SDM as opposed to HSM or USM, who really knows, but each have their failings, whereas screwdriven lenses don't. So is Pentax admitting SDM was a flop - nope, they've been flat out denying that to date. And I'm not convinced it is myself (well maybe a little...), on the overall scheme of things, even though I know there are many stories of SDM motor failures. Last edited by Ash; 11-27-2010 at 05:00 AM.

11-27-2010, 05:06 AM	#6
cameraboy Junior Member Join Date: Sep 2009 Location: Si chang mai nong khai province Posts: 33	response to sdm hi pentaxians, i have the 55f1.4 & as usual to be rebuffed how much speed do most people need to take a snap. loved the k5 review read it while in penang just got back & read the 18-135 review delicious cant wait sorry i kn ow its the wrong place every time to post my sentiments but i am so exited waiting to get the money together for ak5 & a18-135 thanks ian

11-27-2010, 05:21 AM	#8
cameraboy Junior Member Join Date: Sep 2009 Location: Si chang mai nong khai province Posts: 33	re failure. sorry my friend but pentax has never been a failure just slow on the uptake look back in pentax history the first metering camera ETC ETC ETC.

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11-27-2010, 04:44 AM	#3
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521	It is clear that they will not admit this openly. But it is clear that SDM was a failure. It is very slow and the fault rate is too high. I doubt that we will ever see another, new SDM lens. Only time will tell, if the new motor is any better.

11-27-2010, 04:50 AM	#4
Mike Cash Veteran Member Join Date: Jan 2007 Location: Japan Photos: Gallery Posts: 6,950	Hard to beat finger-drive for reliability.

11-27-2010, 04:58 AM	#5
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Originally posted by Mike Cash Hard to beat finger-drive for reliability. Not being cynical are you Mike? That's unlike you. Well, maybe you're right, and the reason why Pentax made quick shift...

11-27-2010, 05:13 AM	#7
jolepp Veteran Member Join Date: Oct 2010 Location: Finland Photos: Albums Posts: 3,196	This could be seen as an implicit admission of failure as it includes abadoning an acronym; if something is successfull and highly regarded (e.g. "SMC") the term for it tends to stick and marketing is about <term> having been improved, <new term> implies replacing something (where the techincal reality and what is implied in marketing lingo don't always meet ;-)

11-27-2010, 05:21 AM	#9
sterretje Veteran Member Join Date: Dec 2008 Location: Roodepoort, South Africa Photos: Gallery \| Albums Posts: 3,561	I've read on the web (interview with Ned ... I think it was) that the DC is for the cheaper lenses and will not replace SDM. I guess time will tell.

11-27-2010, 05:23 AM	#10
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Originally posted by jolepp This could be seen as an implicit admission of failure as it includes abadoning an acronym; if something is successfull and highly regarded (e.g. "SMC") the term for it tends to stick and marketing is about <term> having been improved, <new term> implies replacing something (where the techincal reality and what is implied in marketing lingo don't always meet ;-) Or it may just be that the new technology is nothing like the old one and would be inaccurate to include the old acronym.

11-27-2010, 05:32 AM	#11
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,651	My understanding is the DC motor is not an "improved" SDM motor at all. It is if anything a cheaper version of SDM for lower end lenses. As to whether or not it is any more reliable, no one has any idea. The first DC lenses just hit the market last week -- a little soon to say it is any better than SDM. By all accounts, it is no faster than SDM. The focus throw on the 18-135 is shorter and so it gets places faster, but that is true as well for the DA 17-70 which uses SDM technology and is a pretty fast focuser.

11-27-2010, 05:42 AM	#12
Mike Cash Veteran Member Join Date: Jan 2007 Location: Japan Photos: Gallery Posts: 6,950	Originally posted by cameraboy look back in pentax history the first metering camera ETC ETC ETC. Before Kodak did it in 1938? Originally posted by Ash Well, maybe you're right, and the reason why Pentax made quick shift... If doing it with your fingers is *quick* shift.....then is allowing the camera to do it *slow* shift?

11-27-2010, 07:26 AM	#13
omega leader Veteran Member Join Date: Jan 2008 Location: Niagara Region, Ontario Canada Photos: Gallery Posts: 417	Originally posted by Rondec By all accounts, it is no faster than SDM. The focus throw on the 18-135 is shorter and so it gets places faster, but that is true as well for the DA 17-70 which uses SDM technology and is a pretty fast focuser. From what I've heard this isn't true. The throw on the 18-135mm is apparently 120deg which is long enough for an autofocus lens. Adam posted the review here and it looks good.

11-27-2010, 07:37 AM	#14
kenyee Veteran Member Join Date: Mar 2007 Location: Boston, PRofMA Photos: Albums Posts: 3,026	Originally posted by sterretje I've read on the web (interview with Ned ... I think it was) that the DC is for the cheaper lenses and will not replace SDM. ditto...afaik, DC is cheaper than SDM. Wish they'd use real ring motors for SDM...even Sigma/Tamron have added ring motor technology

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11-27-2010, 07:39 AM	#15
Edgar_in_Indy Veteran Member Join Date: May 2010 Location: Indiana, USA Photos: Gallery Posts: 2,685	If they're getting rid of SDM, I say good riddance. After reading every review I could find of the Pentax 50-135mm and the Sigma 50-150mm, I've decided to go with the Sigma. The performance/reliability issues of the SDM was the deciding factor. The Sigma seems to have comparable image quality and focuses faster. And on top of that, it has a four year warranty compared to the ridiculous 1-year warranty of the Pentax. The skimpy warranty is just too much of a gamble for an $800 lens.