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Lev · 09-12-2017, 04:04 AM

I wonder if there are still issues with SDM AF in newer manufactured DA* lenses? What are the chances that it will fail if I'll get say newest 50-135mm DA* lens? maybe same question will be legal about new 70-200? well, these lenses aren't cheap right?

beholder3 · 09-12-2017, 04:31 AM

The DFA* uses a ring type DC motor and there have been no reports about them failing more than any other drives.

The key SDM risk is that you do not know if the lens is new or has been lying around for years. Relatively recently there were "brandnew" A* lenses on sale.

Lev · 09-12-2017, 05:11 AM

and there's no way to get this information prior purchasing? A* are manual...

gm4life · 09-12-2017, 05:19 AM

Well one way to know if you got a more recent SDM * DA lens is by the box. If you also buy from a good place that has inventory turns in the US like B&H or Adorama you should be fine. They were revised back in like 3 or 4 years ago if memory serves me correct. The boxes I got at the beginning of 2017 for a 55 * and 300 * where the "newer style" silver boxes not the older black ones. Knock on wood mine have been fine.

beholder3 · 09-12-2017, 05:19 AM

Originally posted by Lev

and there's no way to get this information prior purchasing? A* are manual...

You tell me. I am not aware of any.

Dealers can have packs of products lying around in their warehouses or cellars for as long as they like.

hcc · 09-12-2017, 05:21 AM

Originally posted by beholder3

Relatively recently there were "brandnew" A* lenses on sale.

The A* lenses are manual lenses. There is no SDM issues with A* series lenses.

normhead · 09-12-2017, 05:24 AM

Some of us never had SDM issues, well apart from it being pretty slow.

beholder3 · 09-12-2017, 05:25 AM

Originally posted by hcc

The A* lenses are manual lenses. There is no SDM issues with A* series lenses.

The A* lenses are just an example of 20 year old lenses that are sold "brand new", just because someone now decided to sell them.
Obviously the same can happen even easier with DA* lenses.

Selling today doesnt mean manufactured yesterday.

Lev · 09-12-2017, 05:45 AM

Originally posted by beholder3

The A* lenses are just an example of 20 year old lenses that are sold "brand new", just because someone now decided to sell them.
Obviously the same can happen even easier with DA* lenses.

Selling today doesnt mean manufactured yesterday.

I was afraid of this answer

**pepperberry farm** · 09-12-2017, 06:12 AM

is there a way to determine date of manufacture with serial numbers, especially on an issue such as this?

lytrytyr · 09-12-2017, 06:15 AM

Originally posted by pepperberry farm

is there a way to determine date of manufacture with serial numbers, especially on an issue such as this?

Do a statistical analysis on our PF lens serial number database.

BTW, mods, does this thread belong in the SLR lens discussion section?

Lev · 09-12-2017, 06:52 AM

Originally posted by lytrytyr

Do a statistical analysis on our PF lens serial number database.

BTW, mods, does this thread belong in the SLR lens discussion section?

maybe, sorry if I've posted to wrong section.

victormeldrew · 09-12-2017, 10:05 AM

I don't have anything to back this up other than my slightly hazy memory, but I'm sure I remember people having their SDM replaced in service centres after the revision and getting a repeat problem, so it's not necessarily guaranteed that post-revision lenses are faultless...

Regardless, it would be easier and nicer for Pentax to simply admit the issue and to supply some information about the revisions and which lenses have been 'fixed'.

Adam · 09-12-2017, 10:47 AM

Originally posted by Lev

I wonder if there are still issues with SDM AF in newer manufactured DA* lenses? What are the chances that it will fail if I'll get say newest 50-135mm DA* lens? maybe same question will be legal about new 70-200? well, these lenses aren't cheap right?

DA* lenses manufactured after 2014 should have updated hardware which is not as prone to failure, but we still get occasional reports of SDM going bad. If you use your lens regularly (i.e. don't let it sit on the shelf for weeks), this seems to also decrease the chance of SDM failing.

In any case, I'd recommend that you pair your DA* purchases with an extended third-party warranty for the peace of mind.

DC lenses as well as non-Pentax SDM (i.e. in the Tamron clone lenses- 24-70, 15-30, 18-270) are very reliable on the other hand, possibly more so than screwdrive.

normhead · 09-12-2017, 11:37 AM - **1 Like**

Originally posted by Brooke Meyer

Like Norm said, some us have never had trouble. My 2009 vintage 50-135 has been on 7 different K bodies, made hundreds of thousands exposures and is still my preferred portrait lens. My 17-70 was bought used about 5. years ago and is also heavily used. Never an issue with either.

This has always been the issue. If there is a magic return percentage that triggers a recall, then the SDM lenses never reached it. How many lenses are Pentax prepared to repair needlessly to cover a few that fail.

At the time I felt that there was a tolerance issue. To a perfectly spec'd lens there was probably never an issue. A barrel that was a little tight inside a tube causing more than the anticipated friction was burning out the motors in lenses that were harder to rotate than the spec. would predict, and the motor wasn't designed for anything but straight up spec. So if tolerances went your way and the focusing mechanism was to spec or loose, you didn't have an SDM problem. In the case where the out side tube was a little under spec (but still within acceptable tolerances) and the inside was within spec but the tolerances were a little over, those lenses died. Eventually they just put in a circuit board that produced a bit more current and for many (but not all) lenses it solved the problem.

It was a design flaw for sure, and most Pentax users are appalled at the way it was handled, but as far as I know it's ancient history.

09-12-2017, 04:04 AM	#1
Lev Veteran Member Join Date: Aug 2015 Location: Tbilisi, Georgia Posts: 1,197	Do we still have SDM issues? I wonder if there are still issues with SDM AF in newer manufactured DA* lenses? What are the chances that it will fail if I'll get say newest 50-135mm DA* lens? maybe same question will be legal about new 70-200? well, these lenses aren't cheap right?

09-12-2017, 10:47 AM	#14
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,609	Originally posted by Lev I wonder if there are still issues with SDM AF in newer manufactured DA* lenses? What are the chances that it will fail if I'll get say newest 50-135mm DA* lens? maybe same question will be legal about new 70-200? well, these lenses aren't cheap right? DA* lenses manufactured after 2014 should have updated hardware which is not as prone to failure, but we still get occasional reports of SDM going bad. If you use your lens regularly (i.e. don't let it sit on the shelf for weeks), this seems to also decrease the chance of SDM failing. In any case, I'd recommend that you pair your DA* purchases with an extended third-party warranty for the peace of mind. DC lenses as well as non-Pentax SDM (i.e. in the Tamron clone lenses- 24-70, 15-30, 18-270) are very reliable on the other hand, possibly more so than screwdrive. 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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09-12-2017, 04:31 AM	#2
beholder3 Pentaxian Join Date: Dec 2011 Posts: 3,112	The DFA* uses a ring type DC motor and there have been no reports about them failing more than any other drives. The key SDM risk is that you do not know if the lens is new or has been lying around for years. Relatively recently there were "brandnew" A* lenses on sale.

09-12-2017, 05:11 AM	#3
Lev Veteran Member Join Date: Aug 2015 Location: Tbilisi, Georgia Posts: 1,197 Original Poster	and there's no way to get this information prior purchasing? A* are manual...

09-12-2017, 05:19 AM	#4
gm4life Veteran Member Join Date: Dec 2016 Posts: 602	Well one way to know if you got a more recent SDM * DA lens is by the box. If you also buy from a good place that has inventory turns in the US like B&H or Adorama you should be fine. They were revised back in like 3 or 4 years ago if memory serves me correct. The boxes I got at the beginning of 2017 for a 55 * and 300 * where the "newer style" silver boxes not the older black ones. Knock on wood mine have been fine.

09-12-2017, 05:19 AM	#5
beholder3 Pentaxian Join Date: Dec 2011 Posts: 3,112	Originally posted by Lev and there's no way to get this information prior purchasing? A* are manual... You tell me. I am not aware of any. Dealers can have packs of products lying around in their warehouses or cellars for as long as they like.

09-12-2017, 05:21 AM	#6
hcc Pentaxian Join Date: Nov 2009 Location: Brisbane, Australia Photos: Gallery \| Albums Posts: 4,005	Originally posted by beholder3 Relatively recently there were "brandnew" A* lenses on sale. The A* lenses are manual lenses. There is no SDM issues with A* series lenses.

09-12-2017, 05:24 AM	#7
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Some of us never had SDM issues, well apart from it being pretty slow.

09-12-2017, 05:25 AM	#8
beholder3 Pentaxian Join Date: Dec 2011 Posts: 3,112	Originally posted by hcc The A* lenses are manual lenses. There is no SDM issues with A* series lenses. The A* lenses are just an example of 20 year old lenses that are sold "brand new", just because someone now decided to sell them. Obviously the same can happen even easier with DA* lenses. Selling today doesnt mean manufactured yesterday.

09-12-2017, 05:45 AM	#9
Lev Veteran Member Join Date: Aug 2015 Location: Tbilisi, Georgia Posts: 1,197 Original Poster	Originally posted by beholder3 The A* lenses are just an example of 20 year old lenses that are sold "brand new", just because someone now decided to sell them. Obviously the same can happen even easier with DA* lenses. Selling today doesnt mean manufactured yesterday. I was afraid of this answer

09-12-2017, 06:12 AM	#10
pepperberry farm amateur dirt farmer Join Date: Dec 2014 Location: probably out in a field somewhere... Photos: Gallery \| Albums Posts: 41,797	is there a way to determine date of manufacture with serial numbers, especially on an issue such as this?

09-12-2017, 06:15 AM	#11
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by pepperberry farm is there a way to determine date of manufacture with serial numbers, especially on an issue such as this? Do a statistical analysis on our PF lens serial number database. BTW, mods, does this thread belong in the SLR lens discussion section?

09-12-2017, 06:52 AM	#12
Lev Veteran Member Join Date: Aug 2015 Location: Tbilisi, Georgia Posts: 1,197 Original Poster	Originally posted by lytrytyr Do a statistical analysis on our PF lens serial number database. BTW, mods, does this thread belong in the SLR lens discussion section? maybe, sorry if I've posted to wrong section.

09-12-2017, 10:05 AM	#13
victormeldrew Veteran Member Join Date: Jun 2015 Location: South West UK Photos: Albums Posts: 1,493	I don't have anything to back this up other than my slightly hazy memory, but I'm sure I remember people having their SDM replaced in service centres after the revision and getting a repeat problem, so it's not necessarily guaranteed that post-revision lenses are faultless... Regardless, it would be easier and nicer for Pentax to simply admit the issue and to supply some information about the revisions and which lenses have been 'fixed'.

09-12-2017, 11:37 AM - 1 Like	#15
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	Originally posted by Brooke Meyer Like Norm said, some us have never had trouble. My 2009 vintage 50-135 has been on 7 different K bodies, made hundreds of thousands exposures and is still my preferred portrait lens. My 17-70 was bought used about 5. years ago and is also heavily used. Never an issue with either. This has always been the issue. If there is a magic return percentage that triggers a recall, then the SDM lenses never reached it. How many lenses are Pentax prepared to repair needlessly to cover a few that fail. At the time I felt that there was a tolerance issue. To a perfectly spec'd lens there was probably never an issue. A barrel that was a little tight inside a tube causing more than the anticipated friction was burning out the motors in lenses that were harder to rotate than the spec. would predict, and the motor wasn't designed for anything but straight up spec. So if tolerances went your way and the focusing mechanism was to spec or loose, you didn't have an SDM problem. In the case where the out side tube was a little under spec (but still within acceptable tolerances) and the inside was within spec but the tolerances were a little over, those lenses died. Eventually they just put in a circuit board that produced a bit more current and for many (but not all) lenses it solved the problem. It was a design flaw for sure, and most Pentax users are appalled at the way it was handled, but as far as I know it's ancient history.

Do we still have SDM issues?

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