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11-24-2009, 03:28 PM   #31
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To all the people that claim the "SDM issue is over-blown", tell me, why are there no posts about faulty FA lenses? Is there a single thread on this board where MULTIPLE people are posting their problems with their FA 50/1,4? I know there is one where the lens fell apart, but it is not a regular topic on the forum. Also consider the FA 50/1.4 is owned by MANY more people then the DA*'s. What about the 18-55 kit lens? There must be an "Al Gore Billion" of them out there, but has anyone ever had a problem with it?

The other thing to notice, is how many of these lense problem postings are by people that have a long track record both with Pentax and with this forum. Case in point is the OP of this thread. Pentaxpoke, has been posting here for some time now. Its not like the SDM problems are being posted by "one post newbies" that have never used a DSLR. Hell, the OP here has the technical know how to be part of a team that sent a camera into space!

So this is what I see:

Plenty of SDM issue postings by long term members.
No postings about problems with DA or FA lenses.
Pentax has nothing to say about the issue.
People are avoiding the lenses because of the chance of lens failure.

11-24-2009, 03:35 PM   #32
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All correct.
So now where to from here?

Abandon/boycott Pentax's top-end/SDM lenses?
Say nothing and hope the issue will resolve itself?
Or rally petitions, formal complaints, pro-user requests for SDM quality improvements?

Please consider these, particularly the latter imposition, to get something positive out of all these SDM complaint threads that just keep playing back like a broken record.
11-24-2009, 03:56 PM   #33
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It would be hard to imagine that someone at Pentax, hopefully with some influence, isn't aware of this topic and others like it.

If they are reading this topic I would challenge them to respond now, and not later when they have a crisis on their hands.
11-24-2009, 06:10 PM   #34
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QuoteOriginally posted by Eds Quote
philbaum- Yes I did go ahead with the repair. The Sigma of course does not have weather sealing, which I do sometimes need. Frankly though, this whole SDM thing to me is a real bummer as I personally really think the only genuine advantage over all of my non-SDM lenses is the quietness, which to me was never really an issue. My new Sigma focuses plenty fast, and accurately. I'll bet it will for a long time too. Seems better in low light than the Pentax 16-50 I might add.
actually it's becoming more like the advantages of a screw-drive AF lens against a crappy SDM lens. atleast you don't have to suffer SDM failure which could cost you a lot of effort, time, money and missed chances. not to mention FF/BF issues which are highly prevalent in those two zooms. now I know the reason why Pentax had done such focus adjustments. it is to solve such quality inefficiency that some of the widely advertised DA* lenses display.

11-24-2009, 06:17 PM   #35
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QuoteOriginally posted by Ash Quote
All correct.
So now where to from here?

Abandon/boycott Pentax's top-end/SDM lenses?
Say nothing and hope the issue will resolve itself?
Or rally petitions, formal complaints, pro-user requests for SDM quality improvements?

Please consider these, particularly the latter imposition, to get something positive out of all these SDM complaint threads that just keep playing back like a broken record.

from the current trend the DA* zooms are going, I have a feeling that these lenses would fall faster than a rocket in about a year probably selling back to 500 bucks which I believe is still expensive considering the failure record that the lenses hold. 500 bucks wasted for a lens that is uncertain to last after a long time or doomed to fail from the start.

no wonder it is being sold as low as 50 bucks in downtown Vietnam. boy, I would love to ask a favor from someone who's there to ship me a lens which is worth it's real value.
11-24-2009, 06:20 PM   #36
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QuoteOriginally posted by Pentaxor Quote
...not to mention FF/BF issues which are highly prevalent in those two zooms. now I know the reason why Pentax had done such focus adjustments. it is to solve such quality inefficiency that some of the widely advertised DA* lenses display.
Do you imply the FF/BF issues are more pronounced with lenses with HSM? I'm confused.
11-24-2009, 06:51 PM   #37
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QuoteOriginally posted by SOldBear Quote
Do you imply the FF/BF issues are more pronounced with lenses with HSM? I'm confused.
HSM or SDM?

as far as personal experience, not just horror stories from beyond is concerned, YES ! that is one of the big concerns that I have til now aside from the SDM failure. that's why up until now, I refuse to own a copy of the DA*s. tried a lot of them which were being sold by owners and I only see one which doesn't have a worse case of BF and could be easily adjusted. but the uncertainty of SDM failure, nailed the DA*'s coffin for me. as I said I would only get myself a copy if it's worth 50 bucks. I would rather invest my money on the LTDs anytime rather than buy the DA* zooms of what they worth now.
11-25-2009, 01:32 PM   #38
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OK, here is what I encourage everyone to do:

In addition to the current petition to get a firmware update to permit the use of screwdrive on SDM lenses (on those that have it available), which I do think is a good idea, I would like to see pressure mounted on Pentax corp. to focus on their SDM development to create a generation of robust, faster and more reliable AF on their DA* lenses. If we're paying a lot more for them, they ought to live up to their professional-grade status and perform as such for the long term.

My statement sent to them a few weeks ago:
<snip>
I would like to express an area of concern with the current Pentax DA* series lenses that is shared amongst many members of PentaxForums.com. The SDM technology has been an excellent advancement in the modern era of autofocus lenses, however to date there have been numerous personal reports of SDM failures, particularly with the popular DA* 16-50mm and 50-135 lenses.

I have had no reservations on purchasing these lenses myself earlier this year, however the current sentiment on the frequency of SDM failures does send the message that SDM failure is inevitable, and is at least a psychological deterrent from purchasing further SDM lenses. This is unfortunate given the high quality of the DA* lens range and the quality of autofocus provided by rival USM/HSM lenses. Although not an authoritative source of failure rate data, these are the threads illustrating some of the impact of SDM failure on Pentax users:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/75316-sdm-da-f...er-2009-a.html

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/73555-sdm-lens-failures.html

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/81128-more-sdm-problems.html

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/69791-sdm-lens-safe-buy.html

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/67114-another-16-50-dead.html

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/48853-da-16-50...oom-focus.html

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/22187-da-16-50...king-k10d.html


Further to the apparent SDM failure rate, one other area of improvement that I and others in the forum would like to suggest is in autofocus speed and accuracy. There are times, not infrequently, that the lenses lock focus incorrectly, and since it may be difficult to discern this in the viewfinder, leads to out of focus images taken.

The SDM AF speed is also not improved, even at times slower due to hunting, compared to many screwdriven AF lenses of similar focal ranges. Below are a couple of threads that support this concern:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/45227-you-satisfied-sdm.html

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/21436-af-wont-...asionally.html

Overall, it seems the most pressing SDM issue is its apparent high failure rate. The virtue of having autofocus is completely lost when this motor fails. Some members suggest permitting the screw-drive focus mechanism to take over when SDM fails (see https://www.pentaxforums.com/forums/pentax-dslr-discussion/60184-screw-drive-...dm-lenses.html), however I believe this will not curb consumer concern about SDM, which stops many of them from making SDM lens purchases. I also suggest that a quality robust SDM is more worthwhile than the ability to switch from SDM to screw-drive AF, which I believe is only an interim measure to maintain the usefulness of these pro-grade lenses.

The one significant effort that Pentax can do right now to improve customer confidence in SDM lenses, and therefore boost profits from DA* lenses, is to provide an extended warranty.

If these concerns can be acknowledged and worked upon by Pentax, I would easily vouch that a more trusting sentiment on the DA* lenses would ensue, and as a result a much higher purchase rate and investment into Pentax photographic equipment.

Thank you.


Last edited by Ash; 11-25-2009 at 05:11 PM.
11-25-2009, 04:08 PM   #39
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Ash, I couldn't improve on that at all.

My first 50 - 135 DA was bad out of the box and promptly changed by the vendor.

The replacement is a joy to use, except for the nagging worry that a very expensive lens has a reputation for failing and is probably so expensive to repair that the alternative lenses from Sigma or Tamron become attractive replacements, if I could afford or justify the expense in my case.
11-30-2009, 12:59 PM   #40
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After reading a few threads on SDM not waking up, pausing, etc. I found I have a different problem. It's not a DA*, but over the weekend I mounted my Pentax DA 17-70 SDM only lens to my K10D. It's been a great lens so far (bought new in August), however, this weekend it couldn't lock focus. It would just hunt back and forth and finally give up with the blinking hexagon and a blurry image in the viewfinder. I tried AF inside and out, with different subjects and different focal lengths and the lens just wouldn't lock focus. I switched lenses (ltd) and it focused immediately.

Anybody else have this happen to them? Thanks.
11-30-2009, 04:12 PM   #41
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Yes, it happens often with me on my DA* 16-50.
But it only happens when I'm attempting to lock focus on something at infinity, whether in good lighting or not.
I do find that after getting the blinking hexagon, I just finely adjust the focus using the quick shift feature and the focus locks very quickly, so the problem is with the lens and not the camera.

Another bain of SDM AF...
11-30-2009, 04:48 PM   #42
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Yes *sigh* me too. It is completely random, the scene, contrast, light or whatever does not seem to matter. It just does this when it wants to.
On Sunday I was shooting Mom and Baby shots. Pure white backdrop, studio lights and they were both dressed in almost jet black clothing. You could not possibly get better contrast.

My DA*16-50mm just would not lock focus. I wound up switching to an FA24-50mm f4 and the FA50mm f1.4. Both FA's had no issue with the situation. The image quality from the DA* is excellent but this periodic focus issue is such a pain.

Grabbing the quick shift will fix the problem but for me this is not a solution. When I'm getting paid to shoot, I'm in a 'zone' thinking about light, poses etc. The last thing I want to do is stop and fight with a figging lens. It completely breaks the flow.
11-30-2009, 04:51 PM   #43
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Ash care to share the email address you used? Hide it in the 'insert link' feature. I've emailed Pentax Canada and one of the technical support managers, but really didn't get much back from them.

But I'm prepared to share my experiences and be constructive in comments on an improvement.
11-30-2009, 05:00 PM   #44
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No worries Peter.

11-30-2009, 07:30 PM   #45
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Hi,
I just mailed my DA* 16-50 with dead SDM in today. It had three weeks of use followed by four weeks of shelf time. I bought the lens new.
I called Pentax to complain and was transferred to an office above customer support. I talked with a gentleman and expressed my concerns about the long term reliability of the SDM. He wouldn’t engage in any real conversation concerning the SDM, nothing, he just kept interrupting me, telling me to check out dpreview because Pentax (according to him) had posted some numbers on this site which dispelled the idea that there was a high failure rate of SDM. He stated that the overall failure numbers were actually very low AND mostly caused by the lens hitting something, often while in the camera bag. I’m not happy and am considering a brand change.
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