DA* 50-135mm failure

alexeyga · 02-27-2011, 12:40 PM

Unfortunately there are no real alternatives to the 50-135 if size matters... 70-200's from both Tamron and Sigma are really nice, but quite bulky as well... For some people much more compact size of Pentax gear is the only reason they are still with Pentax...

JHD · 02-27-2011, 03:01 PM

Bulk is part and parcel in a high quality lens with 135mm or more in focal length. If you think the Tamron is heavy, try packing the 60-250. For me the extra reach of the Tamron is worth the size and bulk. If size and bilk are real issues, then one has to look no further than the DA 50-200, which by all accounts makes the 50-135 seem like a boat anchor.

twitch · 02-27-2011, 03:19 PM

The old sigma 50-150 was the same size as the 50-135. Unfortunately it seems like the new 50-150 with OS is going to be made in the same lens casing as their 70-200 f2.8 which seems ridiculous.

dgaies · 02-27-2011, 04:00 PM

Originally posted by JHD

If you think the Tamron is heavy, try packing the 60-250.

FWIW, the Tamron 70-200/2.8 and the DA*60-250 actually weight the same (about 1.1 kg). The Tamron is actually a little longer and had a 77mm filter vs the 60-250's 67mm filter. The DA* does extend a few inches at 250mm, and at that point is a little longer than the 70-200, which doesn't extend when zooming (which is nice).

Neither lens is light, but they're both fantastic lenses. The 70-200 is optically outstanding and an excellent value. The 60-250 is also excellent in terms of IQ, and you trade off a little speed (f/4 vs f/2.8) for some extra range on each end. I personally prefer the SDM focus of the 60-250 to the screw drive of the 70-200, but I don't want to start an SDM war and fully acknowledge that many people would prefer the more reliable screw drive of the 70-200.

Comparing the 50-135 to the 70-200, for me it mostly comes down to the size vs whether or not I need the extra reach. More often than not I prefer the extra width and smaller size of the 50-135. Both are excellent optically, and again the focus comes down to preference. However I will say the focus speed of the 50-135 is slower as compared to either the 70-200 or the 60-250. Of all three lenses, the 50-135 has the best overall feel and build (IMO), aside from potential reliability issues.

Last edited by dgaies; 02-27-2011 at 04:13 PM.

benjikan · 02-28-2011, 12:53 AM

Incredible. Pentax replaced my SDM motor in my 50-135 about a year ago. I did not use it once ever since the repair. I went to use it about two weeks ago and it was dead. Sent it back to Pentax with my 16-50 to have both repaired...

sean · 02-28-2011, 07:40 AM

@Benjikan: Sorry to hear that. I wonder if they die because we don't use them for a month or more?
If that's the case, maybe the trick is to connect them to a camera every week or so? Not an acceptable solution for top shelf lenses, but if this was formally documented somewhere, at least we'd know.

aleonx3 · 02-28-2011, 08:22 AM

I think some of us would like to know if it is technically impossible to have the camera use the screw drive mechanism on the lens in the case of SDM failure. This type of fix (either via firmware or SDM replacement motor) will go a long way to mitigate the current problems people experienced on the DA* lenses.

**hyyz** · 02-28-2011, 09:03 AM

Originally posted by aleonx3

I think some of us would like to know if it is technically impossible to have the camera use the screw drive mechanism on the lens in the case of SDM failure. This type of fix (either via firmware or SDM replacement motor) will go a long way to mitigate the current problems people experienced on the DA* lenses.

I'm afraid that may cause more issues. See my observation on 50-135mm here:
Observation on DA* 50-135mm AF/MF operations .

I remember I read somewhere that Pentax has stated that they won't introduce any new lens with duo-AF mechanisms. But I can't now remember where to find the source.

aleonx3 · 02-28-2011, 09:19 AM

Originally posted by hyyz

I'm afraid that may cause more issues. See my observation on 50-135mm here:
Observation on DA* 50-135mm AF/MF operations .

I remember I read somewhere that Pentax has stated that they won't introduce any new lens with duo-AF mechanisms. But I can't now remember where to find the source.

I wonder if insulating the SDM contacts on the lens itself from the camera would fool the camera that it is not an SDM lens and to use the screw drive focus mechanism.

calicojack · 02-28-2011, 10:19 AM

Originally posted by aleonx3

I wonder if insulating the SDM contacts on the lens itself from the camera would fool the camera that it is not an SDM lens and to use the screw drive focus mechanism.

I've read that covering the contacts won't work. I use mine on a K10D and actually did a firmware downgrade back to a "hacked" V1.1 and back to the official V1.2. My 50-135 now focus' just fine using the screwdrive on my K10D but can only be manually focused on my wife's K200D. (She uses a DA 55-300 anyway.)

aleonx3 · 02-28-2011, 10:39 AM

So, does that mean that firmware change (option) in K-7 or K-5 can help? But then, if there is such an option, would that deny also you from using the DA 17-70mm (SDM only) lens?

normhead · 02-28-2011, 10:48 AM

The problem with things like this is, once you've had a lens fail, and they've replaced the motor, gears etc. it make you wonder if there is another issue. Obviously Pentax felt it was a defective motor- gear system, but what it there are other resistances in the lens, that are causing a good motor and gear system to work too hard? I remember the old thing about computers, "if it hasn't failed in three months, it probably won't fail for 5 years." All my experience with other mechanical systems is similar. It is often not the part that failed that was the problem. It takes a top notch technician to diagnose. Or as friend in the auto repair business once said, anyone can fix a problem, if they know what it is. The good mechanics know what the problem is, without a couple of false starts before they get it right.

Good luck with your lens, but, I really wish they'd just give you a new one.

dgaies · 02-28-2011, 10:48 AM

Originally posted by aleonx3

So, does that mean that firmware change (option) in K-7 or K-5 can help? But then, if there is such an option, would that deny also you from using the DA 17-70mm (SDM only) lens?

A firmware change could enable it on a K-7 or K-5, but it will (almost certainly) never happen. People have been "asking" for such an option for a several years now without any success or feedback. However, if such a modification to the firmware were made, there's no reason it couldn't be a lens specific option.

calicojack · 02-28-2011, 10:50 AM

As I understand it, the K10D is the last of the original only screw drive AF cameras that were built. It was upgraded in its firmware V1.3 to allow SDM AF. With V1.3 and an SDM lens mounted, the screw drive is disabled. Mount a non SDM lens and it screw drives the AF. I don't think that Pentax has released any firmware changes for any of the bodies that will allow turning back the SDM drive to screw drive. That's why the K10D need the "Hacked" version of 1.1 to go backwards.
Yes, one of the difficulties I now have is that any of the SDM only lenses will not autofocus on my K10D unless I reinstall V1.3 firmware. It's not a big problem for me since I don't have any SDM only lenses (yet).

sean · 05-15-2011, 12:34 AM

Got it back. Pentax Canada charged me $225, saying the front ring was cracked. I'm a bit skeptical, but I'm happy to have this lens back in time for summer.

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02-27-2011, 12:40 PM	#16
alexeyga Veteran Member Join Date: Dec 2008 Location: Montreal, Canada Posts: 838	Unfortunately there are no real alternatives to the 50-135 if size matters... 70-200's from both Tamron and Sigma are really nice, but quite bulky as well... For some people much more compact size of Pentax gear is the only reason they are still with Pentax...

02-27-2011, 03:01 PM	#17
JHD Veteran Member Join Date: Jan 2010 Photos: Albums Posts: 1,406	Bulk is part and parcel in a high quality lens with 135mm or more in focal length. If you think the Tamron is heavy, try packing the 60-250. For me the extra reach of the Tamron is worth the size and bulk. If size and bilk are real issues, then one has to look no further than the DA 50-200, which by all accounts makes the 50-135 seem like a boat anchor.

02-27-2011, 03:19 PM	#18
twitch Veteran Member Join Date: Nov 2009 Posts: 4,571	The old sigma 50-150 was the same size as the 50-135. Unfortunately it seems like the new 50-150 with OS is going to be made in the same lens casing as their 70-200 f2.8 which seems ridiculous.

02-27-2011, 04:00 PM	#19
dgaies Veteran Member Join Date: Oct 2009 Location: Maryland / Washington DC Posts: 3,917	Originally posted by JHD If you think the Tamron is heavy, try packing the 60-250. FWIW, the Tamron 70-200/2.8 and the DA60-250 actually weight the same (about 1.1 kg). The Tamron is actually a little longer and had a 77mm filter vs the 60-250's 67mm filter. The DA does extend a few inches at 250mm, and at that point is a little longer than the 70-200, which doesn't extend when zooming (which is nice). Neither lens is light, but they're both fantastic lenses. The 70-200 is optically outstanding and an excellent value. The 60-250 is also excellent in terms of IQ, and you trade off a little speed (f/4 vs f/2.8) for some extra range on each end. I personally prefer the SDM focus of the 60-250 to the screw drive of the 70-200, but I don't want to start an SDM war and fully acknowledge that many people would prefer the more reliable screw drive of the 70-200. Comparing the 50-135 to the 70-200, for me it mostly comes down to the size vs whether or not I need the extra reach. More often than not I prefer the extra width and smaller size of the 50-135. Both are excellent optically, and again the focus comes down to preference. However I will say the focus speed of the 50-135 is slower as compared to either the 70-200 or the 60-250. Of all three lenses, the 50-135 has the best overall feel and build (IMO), aside from potential reliability issues. Last edited by dgaies; 02-27-2011 at 04:13 PM.

02-28-2011, 12:53 AM	#20
benjikan Veteran Member Join Date: Jan 2007 Location: Paris, France Photos: Gallery Posts: 4,308	Incredible. Pentax replaced my SDM motor in my 50-135 about a year ago. I did not use it once ever since the repair. I went to use it about two weeks ago and it was dead. Sent it back to Pentax with my 16-50 to have both repaired...

02-28-2011, 07:40 AM	#21
sean New Member Join Date: May 2009 Location: Fort Chipewyan, AB, Canada Photos: Gallery Posts: 24 Original Poster	@Benjikan: Sorry to hear that. I wonder if they die because we don't use them for a month or more? If that's the case, maybe the trick is to connect them to a camera every week or so? Not an acceptable solution for top shelf lenses, but if this was formally documented somewhere, at least we'd know.

02-28-2011, 08:22 AM	#22
aleonx3 Veteran Member Join Date: Jul 2007 Location: Brampton, Ontario Photos: Gallery \| Albums Posts: 3,996	I think some of us would like to know if it is technically impossible to have the camera use the screw drive mechanism on the lens in the case of SDM failure. This type of fix (either via firmware or SDM replacement motor) will go a long way to mitigate the current problems people experienced on the DA* lenses.

02-28-2011, 09:03 AM	#23
hyyz Site Supporter Join Date: Jan 2008 Location: Michigan Posts: 478	Originally posted by aleonx3 I think some of us would like to know if it is technically impossible to have the camera use the screw drive mechanism on the lens in the case of SDM failure. This type of fix (either via firmware or SDM replacement motor) will go a long way to mitigate the current problems people experienced on the DA* lenses. I'm afraid that may cause more issues. See my observation on 50-135mm here: Observation on DA* 50-135mm AF/MF operations . I remember I read somewhere that Pentax has stated that they won't introduce any new lens with duo-AF mechanisms. But I can't now remember where to find the source.

02-28-2011, 09:19 AM	#24
aleonx3 Veteran Member Join Date: Jul 2007 Location: Brampton, Ontario Photos: Gallery \| Albums Posts: 3,996	Originally posted by hyyz I'm afraid that may cause more issues. See my observation on 50-135mm here: Observation on DA* 50-135mm AF/MF operations . I remember I read somewhere that Pentax has stated that they won't introduce any new lens with duo-AF mechanisms. But I can't now remember where to find the source. I wonder if insulating the SDM contacts on the lens itself from the camera would fool the camera that it is not an SDM lens and to use the screw drive focus mechanism.

02-28-2011, 10:19 AM	#25
calicojack Inactive Account Join Date: Mar 2007 Location: Long Island, N.Y. Photos: Gallery Posts: 1,124	Originally posted by aleonx3 I wonder if insulating the SDM contacts on the lens itself from the camera would fool the camera that it is not an SDM lens and to use the screw drive focus mechanism. I've read that covering the contacts won't work. I use mine on a K10D and actually did a firmware downgrade back to a "hacked" V1.1 and back to the official V1.2. My 50-135 now focus' just fine using the screwdrive on my K10D but can only be manually focused on my wife's K200D. (She uses a DA 55-300 anyway.)

02-28-2011, 10:39 AM	#26
aleonx3 Veteran Member Join Date: Jul 2007 Location: Brampton, Ontario Photos: Gallery \| Albums Posts: 3,996	So, does that mean that firmware change (option) in K-7 or K-5 can help? But then, if there is such an option, would that deny also you from using the DA 17-70mm (SDM only) lens?

02-28-2011, 10:48 AM	#27
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	The problem with things like this is, once you've had a lens fail, and they've replaced the motor, gears etc. it make you wonder if there is another issue. Obviously Pentax felt it was a defective motor- gear system, but what it there are other resistances in the lens, that are causing a good motor and gear system to work too hard? I remember the old thing about computers, "if it hasn't failed in three months, it probably won't fail for 5 years." All my experience with other mechanical systems is similar. It is often not the part that failed that was the problem. It takes a top notch technician to diagnose. Or as friend in the auto repair business once said, anyone can fix a problem, if they know what it is. The good mechanics know what the problem is, without a couple of false starts before they get it right. Good luck with your lens, but, I really wish they'd just give you a new one.

02-28-2011, 10:48 AM	#28
dgaies Veteran Member Join Date: Oct 2009 Location: Maryland / Washington DC Posts: 3,917	Originally posted by aleonx3 So, does that mean that firmware change (option) in K-7 or K-5 can help? But then, if there is such an option, would that deny also you from using the DA 17-70mm (SDM only) lens? A firmware change could enable it on a K-7 or K-5, but it will (almost certainly) never happen. People have been "asking" for such an option for a several years now without any success or feedback. However, if such a modification to the firmware were made, there's no reason it couldn't be a lens specific option.

02-28-2011, 10:50 AM	#29
calicojack Inactive Account Join Date: Mar 2007 Location: Long Island, N.Y. Photos: Gallery Posts: 1,124	As I understand it, the K10D is the last of the original only screw drive AF cameras that were built. It was upgraded in its firmware V1.3 to allow SDM AF. With V1.3 and an SDM lens mounted, the screw drive is disabled. Mount a non SDM lens and it screw drives the AF. I don't think that Pentax has released any firmware changes for any of the bodies that will allow turning back the SDM drive to screw drive. That's why the K10D need the "Hacked" version of 1.1 to go backwards. Yes, one of the difficulties I now have is that any of the SDM only lenses will not autofocus on my K10D unless I reinstall V1.3 firmware. It's not a big problem for me since I don't have any SDM only lenses (yet).

05-15-2011, 12:34 AM	#30
sean New Member Join Date: May 2009 Location: Fort Chipewyan, AB, Canada Photos: Gallery Posts: 24 Original Poster	Got it back. Pentax Canada charged me $225, saying the front ring was cracked. I'm a bit skeptical, but I'm happy to have this lens back in time for summer.