Buy an SDM lens recently?

gnaztee · 01-12-2011, 11:00 AM

Originally posted by JHD

New or used, anyone who buys an SDM lens should know the risk they're taking and that failure is highly probable.

That should read "highly possible"

PentaxPoke · 01-12-2011, 11:13 AM

Originally posted by gnaztee

That should read "highly possible"

Every SDM lens I owned failed one way or another. All were due to QC problems, and three were due to SDM failure.

I'm just sayin...

gnaztee · 01-12-2011, 11:21 AM

Originally posted by PentaxPoke

Every SDM lens I owned failed one way or another. All were due to QC problems, and three were due to SDM failure.

I'm just sayin...

And my SDM lens hasn't failed, and there are numerous web forum posts about SDM lenses that have failed, and numerous posts about SDM lenses that haven't failed, and so...we can conclude that it is possible SDM will fail, but in the absence of hard statistics have no clue whether it's probable SDM will fail.

I'm just sayin' too

dgaies · 01-12-2011, 11:35 AM

Originally posted by gnaztee

And my SDM lens hasn't failed, and there are numerous web forum posts about SDM lenses that have failed, and numerous posts about SDM lenses that haven't failed, and so...we can conclude that that it is possible SDM will fail, but in the absence of hard statistics have no clue whether it's probable SDM will fail.

I'm just sayin' too

Agreed.

No one knows the exact numbers, aside from Pentax themselves, and I doubt they would be forthcoming with the information.

That said, it's hardly "probable" that SDM will fail on a given lens, sugeesting that over the life of a given lens it's got a better than 50% chance of failing. I have 4 SDM lenses and I fully acknowledge that it's possible (maybe even somewhat likely) that at some point one of them will fail. I also have no doubt that it is significantly more probable for an SDM lens to fail compared to a screw-driven lens.

And if someone is risk-adverse, then I would recommend staying away from SDM lenses altogether as the constant wondering "when is my lenses going to die" could potentially take away the enjoyment of the lens while it's not broken. However, for someone who is aware of the potential risk (which, again, is possible, not probable) and who is aware of the consequences of a failure (a $200 repair), there are many fine SDM lenses that are more than worth considering despite the potential for failure.

sewebster · 01-12-2011, 12:20 PM

Originally posted by dgaies

That said, it's hardly "probable" that SDM will fail on a given lens, sugeesting that over the life of a given lens it's got a better than 50% chance of failing.

But what is the life of a lens? How about, 40 years? Lots of lenses that old still seem to work. It wouldn't take too much to convince me that it is _probable_ for SDM to fail in that time. However, perhaps that is entirely reasonable and something that people are willing to accept.

While silent in-lens motors (and other electronics such as IS/VR) have advantages, it is one more thing to break and may limit the lifespan of modern lenses. Lenses might not be as much of an "investment" as they once were.

dgaies · 01-12-2011, 12:32 PM

Originally posted by sewebster

But what is the life of a lens? How about, 40 years? Lots of lenses that old still seem to work. It wouldn't take too much to convince me that it is _probable_ for SDM to fail in that time. However, perhaps that is entirely reasonable and something that people are willing to accept.

While silent in-lens motors (and other electronics such as IS/VR) have advantages, it is one more thing to break and may limit the lifespan of modern lenses. Lenses might not be as much of an "investment" as they once were.

I'll agree with that; over 40 years it most likely is probable that the SDM would fail. There's no question that once you start adding things like motors other electronic components to lenses that the expected life of the lens (without repairing it) gets shortert. But it's the same with other things, like cars and TVs (and lots of other products). As you start adding more features they require more potential repairs down the road to keep them functional. And sometimes, but not always, these repairs are cost prohibitive relative to the replacement cost.

I suppose I should amend my last post to say if you are risk-adverse or want the best chance of having your lens work in 40 years, you should stay away from SDM. On the other hand, if over a long period of time you have to replace the SDM motor every 5 years at a cost of $150-200, there are probably some people (myself included) that would be willing to factor that into the "real cost" of owning the lens and then make my decsion accordingly.

**Rondec** · 01-12-2011, 01:15 PM

Originally posted by dgaies

I'll agree with that; over 40 years it most likely is probable that the SDM would fail. There's no question that once you start adding things like motors other electronic components to lenses that the expected life of the lens (without repairing it) gets shortert. But it's the same with other things, like cars and TVs (and lots of other products). As you start adding more features they require more potential repairs down the road to keep them functional. And sometimes, but not always, these repairs are cost prohibitive relative to the replacement cost.

I suppose I should amend my last post to say if you are risk-adverse or want the best chance of having your lens work in 40 years, you should stay away from SDM. On the other hand, if over a long period of time you have to replace the SDM motor every 5 years at a cost of $150-200, there are probably some people (myself included) that would be willing to factor that into the "real cost" of owning the lens and then make my decsion accordingly.

Most cars now have power windows. I have had a couple of vehicles where those motors burned out and they are quite expensive to replace. There are all sorts of other places where devices have gotten more complex and therefore more likely to break.

In lens motors do break. This is true for every camera company out there. Particularly with the cheaper end "silent wave" motors, the rate is not infrequent. Unfortunately, to this point I have only heard people who have had SDM motors break say that they all break and those who haven't had problems say that they are reliable.

For those who really want a lens that will "last forever," manual focus is definitely the way to go. Probably look into one of the cheap zeiss lenses that are available new. Probably best not to use it either, since if you drop it there will certainly be no warranty coverage.

Hound Tooth · 01-12-2011, 06:38 PM

Originally posted by Rondec

Most cars now have power windows. I have had a couple of vehicles where those motors burned out and they are quite expensive to replace. There are all sorts of other places where devices have gotten more complex and therefore more likely to break.

That's a terrible analogy.

...besides, power window motors last longer than SDM motors.

**Rondec** · 01-12-2011, 07:01 PM

Originally posted by Hound Tooth

That's a terrible analogy.

...besides, power window motors last longer than SDM motors.

Yes, but since I have experienced power window motors burn out and I can find other people on the internet with similar experiences, clearly the rate of burn out of these motors eventually approaches 100 percent. Not so different from SDM, you see.

dgaies · 01-12-2011, 07:35 PM

Originally posted by Rondec

Yes, but since I have experienced power window motors burn out and I can find other people on the internet with similar experiences, clearly the rate of burn out of these motors eventually approaches 100 percent. Not so different from SDM, you see.

Ironically, I've had to replace a power window motor in my car once as well.

I can now conclude that if you own a car with power windows and SDM lenses, one of the two will fail, but not both

JHD · 01-12-2011, 07:53 PM

Comparing the reliability of power windows to SDM lenses is laughable. Thanks God Pentax doesn't make power windows!

dgaies · 01-12-2011, 08:06 PM

Originally posted by JHD

Comparing the reliability of power windows to SDM lenses is laughable. Thanks God Pentax doesn't make power windows!

Nobody is actually comparing the two in terms of reliability. I think we can all agree that power windows are orders of magnitude more reliable than the motor in SDM lenses. However, that was hardly the point of the original analogy, and I am fairly certain you knew that.

I realize you hate SDM lenses and I can only assume that you've had at least one bad experience with them personally. I'm not a Pentax/SDM apologist and would like nothing more than for SDM lenses to be replaced with something more reliable and faster. I think that the move to SDM lenses on Pentax's higher end glass, and their associated QC issues, has done considerable harm to Pentax's sales and reputation.

That said, the notion that people should never buy one because of the possibility that they may fail outside the (short) one year warranty doesn't make sense. I buy lots of things that I fully understand may break and need repair outside it's warranty period (my car being one of those). It just doesn't make sense (to me) to dismiss every single DA* SDM lens because of possibility it may fail and need its motor replaced at some point down the road.

johnmflores · 01-12-2011, 08:38 PM

Originally posted by dgaies

Nobody is actually comparing the two in terms of reliability. I think we can all agree that power windows are orders of magnitude more reliable than the motor in SDM lenses. However, that was hardly the point of the original analogy, and I am fairly certain you knew that.

I realize you hate SDM lenses and I can only assume that you've had at least one bad experience with them personally. I'm not a Pentax/SDM apologist and would like nothing more than for SDM lenses to be replaced with something more reliable and faster. I think that the move to SDM lenses on Pentax's higher end glass, and their associated QC issues, has done considerable harm to Pentax's sales and reputation.

That said, the notion that people should never buy one because of the possibility that they may fail outside the (short) one year warranty doesn't make sense. I buy lots of things that I fully understand may break and need repair outside it's warranty period (my car being one of those). It just doesn't make sense (to me) to dismiss every single DA* SDM lens because of possibility it may fail and need its motor replaced at some point down the road.

Stop talking sensibly. You're making the Internets boring.

sewebster · 01-12-2011, 08:50 PM

I wish my car didn't have power windows because they are getting really slow. I'm not sure what this means about SDM lenses though.

Hound Tooth · 01-12-2011, 09:05 PM

Originally posted by dgaies

Nobody is actually comparing the two in terms of reliability. I think we can all agree that power windows are orders of magnitude more reliable than the motor in SDM lenses. However, that was hardly the point of the original analogy, and I am fairly certain you knew that.

It's still a terrible, pointless analogy.

However I'll take your ridiculous analogy and make it relevant: imagine a vehicle manufacturer that includes both power windows AND a manual window crank. But you're forbidden to use that crank when the power window motor fails.

Oh, and the power window motor is only warrantied for a year, even though it's failure-prone.

And it's only in the high-end luxury cars that they market to their best customers.

01-12-2011, 11:21 AM	#93
gnaztee Veteran Member Join Date: Nov 2007 Location: West Palm Beach, FL Posts: 772	Originally posted by PentaxPoke Every SDM lens I owned failed one way or another. All were due to QC problems, and three were due to SDM failure. I'm just sayin... And my SDM lens hasn't failed, and there are numerous web forum posts about SDM lenses that have failed, and numerous posts about SDM lenses that haven't failed, and so...we can conclude that it is possible SDM will fail, but in the absence of hard statistics have no clue whether it's probable SDM will fail. I'm just sayin' too Last edited by gnaztee; 01-12-2011 at 11:37 AM. Reason: double word

01-12-2011, 07:35 PM	#100
dgaies Veteran Member Join Date: Oct 2009 Location: Maryland / Washington DC Posts: 3,917	Originally posted by Rondec Yes, but since I have experienced power window motors burn out and I can find other people on the internet with similar experiences, clearly the rate of burn out of these motors eventually approaches 100 percent. Not so different from SDM, you see. Ironically, I've had to replace a power window motor in my car once as well. I can now conclude that if you own a car with power windows and SDM lenses, one of the two will fail, but not both Last edited by dgaies; 01-12-2011 at 07:51 PM.

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01-12-2011, 11:00 AM	#91
gnaztee Veteran Member Join Date: Nov 2007 Location: West Palm Beach, FL Posts: 772	Originally posted by JHD New or used, anyone who buys an SDM lens should know the risk they're taking and that failure is highly probable. That should read "highly possible"

01-12-2011, 11:13 AM	#92
PentaxPoke Veteran Member Join Date: Jan 2008 Location: Oklahoma Posts: 1,411	Originally posted by gnaztee That should read "highly possible" Every SDM lens I owned failed one way or another. All were due to QC problems, and three were due to SDM failure. I'm just sayin...

01-12-2011, 11:35 AM	#94
dgaies Veteran Member Join Date: Oct 2009 Location: Maryland / Washington DC Posts: 3,917	Originally posted by gnaztee And my SDM lens hasn't failed, and there are numerous web forum posts about SDM lenses that have failed, and numerous posts about SDM lenses that haven't failed, and so...we can conclude that that it is possible SDM will fail, but in the absence of hard statistics have no clue whether it's probable SDM will fail. I'm just sayin' too Agreed. No one knows the exact numbers, aside from Pentax themselves, and I doubt they would be forthcoming with the information. That said, it's hardly "probable" that SDM will fail on a given lens, sugeesting that over the life of a given lens it's got a better than 50% chance of failing. I have 4 SDM lenses and I fully acknowledge that it's possible (maybe even somewhat likely) that at some point one of them will fail. I also have no doubt that it is significantly more probable for an SDM lens to fail compared to a screw-driven lens. And if someone is risk-adverse, then I would recommend staying away from SDM lenses altogether as the constant wondering "when is my lenses going to die" could potentially take away the enjoyment of the lens while it's not broken. However, for someone who is aware of the potential risk (which, again, is possible, not probable) and who is aware of the consequences of a failure (a $200 repair), there are many fine SDM lenses that are more than worth considering despite the potential for failure.

01-12-2011, 12:20 PM	#95
sewebster Veteran Member Join Date: Jun 2008 Location: Vancouver, BC Photos: Gallery Posts: 544	Originally posted by dgaies That said, it's hardly "probable" that SDM will fail on a given lens, sugeesting that over the life of a given lens it's got a better than 50% chance of failing. But what is the life of a lens? How about, 40 years? Lots of lenses that old still seem to work. It wouldn't take too much to convince me that it is _probable_ for SDM to fail in that time. However, perhaps that is entirely reasonable and something that people are willing to accept. While silent in-lens motors (and other electronics such as IS/VR) have advantages, it is one more thing to break and may limit the lifespan of modern lenses. Lenses might not be as much of an "investment" as they once were.

01-12-2011, 12:32 PM	#96
dgaies Veteran Member Join Date: Oct 2009 Location: Maryland / Washington DC Posts: 3,917	Originally posted by sewebster But what is the life of a lens? How about, 40 years? Lots of lenses that old still seem to work. It wouldn't take too much to convince me that it is _probable_ for SDM to fail in that time. However, perhaps that is entirely reasonable and something that people are willing to accept. While silent in-lens motors (and other electronics such as IS/VR) have advantages, it is one more thing to break and may limit the lifespan of modern lenses. Lenses might not be as much of an "investment" as they once were. I'll agree with that; over 40 years it most likely is probable that the SDM would fail. There's no question that once you start adding things like motors other electronic components to lenses that the expected life of the lens (without repairing it) gets shortert. But it's the same with other things, like cars and TVs (and lots of other products). As you start adding more features they require more potential repairs down the road to keep them functional. And sometimes, but not always, these repairs are cost prohibitive relative to the replacement cost. I suppose I should amend my last post to say if you are risk-adverse or want the best chance of having your lens work in 40 years, you should stay away from SDM. On the other hand, if over a long period of time you have to replace the SDM motor every 5 years at a cost of $150-200, there are probably some people (myself included) that would be willing to factor that into the "real cost" of owning the lens and then make my decsion accordingly.

01-12-2011, 01:15 PM	#97
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,652	Originally posted by dgaies I'll agree with that; over 40 years it most likely is probable that the SDM would fail. There's no question that once you start adding things like motors other electronic components to lenses that the expected life of the lens (without repairing it) gets shortert. But it's the same with other things, like cars and TVs (and lots of other products). As you start adding more features they require more potential repairs down the road to keep them functional. And sometimes, but not always, these repairs are cost prohibitive relative to the replacement cost. I suppose I should amend my last post to say if you are risk-adverse or want the best chance of having your lens work in 40 years, you should stay away from SDM. On the other hand, if over a long period of time you have to replace the SDM motor every 5 years at a cost of $150-200, there are probably some people (myself included) that would be willing to factor that into the "real cost" of owning the lens and then make my decsion accordingly. Most cars now have power windows. I have had a couple of vehicles where those motors burned out and they are quite expensive to replace. There are all sorts of other places where devices have gotten more complex and therefore more likely to break. In lens motors do break. This is true for every camera company out there. Particularly with the cheaper end "silent wave" motors, the rate is not infrequent. Unfortunately, to this point I have only heard people who have had SDM motors break say that they all break and those who haven't had problems say that they are reliable. For those who really want a lens that will "last forever," manual focus is definitely the way to go. Probably look into one of the cheap zeiss lenses that are available new. Probably best not to use it either, since if you drop it there will certainly be no warranty coverage.

01-12-2011, 06:38 PM	#98
Hound Tooth Banned Join Date: Nov 2010 Location: Williston, VT Posts: 268	Originally posted by Rondec Most cars now have power windows. I have had a couple of vehicles where those motors burned out and they are quite expensive to replace. There are all sorts of other places where devices have gotten more complex and therefore more likely to break. That's a terrible analogy. ...besides, power window motors last longer than SDM motors.

01-12-2011, 07:01 PM	#99
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,652	Originally posted by Hound Tooth That's a terrible analogy. ...besides, power window motors last longer than SDM motors. Yes, but since I have experienced power window motors burn out and I can find other people on the internet with similar experiences, clearly the rate of burn out of these motors eventually approaches 100 percent. Not so different from SDM, you see.

01-12-2011, 07:53 PM	#101
JHD Veteran Member Join Date: Jan 2010 Photos: Albums Posts: 1,406	Comparing the reliability of power windows to SDM lenses is laughable. Thanks God Pentax doesn't make power windows!

01-12-2011, 08:06 PM	#102
dgaies Veteran Member Join Date: Oct 2009 Location: Maryland / Washington DC Posts: 3,917	Originally posted by JHD Comparing the reliability of power windows to SDM lenses is laughable. Thanks God Pentax doesn't make power windows! Nobody is actually comparing the two in terms of reliability. I think we can all agree that power windows are orders of magnitude more reliable than the motor in SDM lenses. However, that was hardly the point of the original analogy, and I am fairly certain you knew that. I realize you hate SDM lenses and I can only assume that you've had at least one bad experience with them personally. I'm not a Pentax/SDM apologist and would like nothing more than for SDM lenses to be replaced with something more reliable and faster. I think that the move to SDM lenses on Pentax's higher end glass, and their associated QC issues, has done considerable harm to Pentax's sales and reputation. That said, the notion that people should never buy one because of the possibility that they may fail outside the (short) one year warranty doesn't make sense. I buy lots of things that I fully understand may break and need repair outside it's warranty period (my car being one of those). It just doesn't make sense (to me) to dismiss every single DA* SDM lens because of possibility it may fail and need its motor replaced at some point down the road.

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01-12-2011, 08:38 PM	#103
johnmflores Veteran Member Join Date: Apr 2009 Location: Somerville, NJ Photos: Gallery \| Albums Posts: 5,361	Originally posted by dgaies Nobody is actually comparing the two in terms of reliability. I think we can all agree that power windows are orders of magnitude more reliable than the motor in SDM lenses. However, that was hardly the point of the original analogy, and I am fairly certain you knew that. I realize you hate SDM lenses and I can only assume that you've had at least one bad experience with them personally. I'm not a Pentax/SDM apologist and would like nothing more than for SDM lenses to be replaced with something more reliable and faster. I think that the move to SDM lenses on Pentax's higher end glass, and their associated QC issues, has done considerable harm to Pentax's sales and reputation. That said, the notion that people should never buy one because of the possibility that they may fail outside the (short) one year warranty doesn't make sense. I buy lots of things that I fully understand may break and need repair outside it's warranty period (my car being one of those). It just doesn't make sense (to me) to dismiss every single DA* SDM lens because of possibility it may fail and need its motor replaced at some point down the road. Stop talking sensibly. You're making the Internets boring.

01-12-2011, 08:50 PM	#104
sewebster Veteran Member Join Date: Jun 2008 Location: Vancouver, BC Photos: Gallery Posts: 544	I wish my car didn't have power windows because they are getting really slow. I'm not sure what this means about SDM lenses though.

01-12-2011, 09:05 PM	#105
Hound Tooth Banned Join Date: Nov 2010 Location: Williston, VT Posts: 268	Originally posted by dgaies Nobody is actually comparing the two in terms of reliability. I think we can all agree that power windows are orders of magnitude more reliable than the motor in SDM lenses. However, that was hardly the point of the original analogy, and I am fairly certain you knew that. It's still a terrible, pointless analogy. However I'll take your ridiculous analogy and make it relevant: imagine a vehicle manufacturer that includes both power windows AND a manual window crank. But you're forbidden to use that crank when the power window motor fails. Oh, and the power window motor is only warrantied for a year, even though it's failure-prone. And it's only in the high-end luxury cars that they market to their best customers.