[thejediknight]

I have my heart set on getting a k-5 and I thought buying the DA 16-50mm and the DA 50-135mm lenses would be nice, but I've realized that the SDM motors on these lenses fail a lot from looking at the threads here. My questions are:

• What lenses would you suggest as similar lenses (with the same good optical quality) if I didn't go for the DAs?
• Most of the complaints about SDM failures seem to be from 2007-2009. Are the new lenses from 2009-2010 failing as well? I am hoping that maybe Pentax fixed the QA/design issues in the recent lenses?
• Does anyone know if Pentax officially acknowledged fixing these issues?
• Thanks!

[dgaies]

What lenses would you suggest as similar lenses (with the same good optical quality) if I didn't go for the DAs?

I would suggest looking at the Tamron 17-50/2.8 as a possible alternative to the DA*16-50/2.8. You could also try the Tamron 70-200/2.8 instead of the DA*50-135, but obviously the focal length is shifted a bit. Sigma used to make a 50-150 that seems to get a lot of praise. I've never owned one, so I can't say for certain if the IQ is as good as the DA*, but I suspect it's not too far off.

Most of the complaints about SDM failures seem to be from 2007-2009. Are the new lenses from 2009-2010 failing as well? I am hoping that maybe Pentax fixed the QA/design issues in the recent lenses?

There is no reason to believe there has been any design change that addressed the issue. There is speculation, but I believe it is unfounded. Whether Pentax's QA/QC got any better would just be a guess, although again I have no reason to believe it did.

Does anyone know if Pentax officially acknowledged fixing these issues?

No, they have not acknowledged anything as far as I know.

Thanks!

You're welcome

Now despite my answers above, I really like my DA* lenses, especially the 50-135. I realize the SDM motor is the weak link in their design, but I also try not to worry about it either. There's are a ton of threads which talk about the issue, so I would recommend doing a little more reading on the subject and then coming to your own conclusion about whether or not buying a DA* lens is right for you based on the risk, IQ, cost, etc.

[psychdoc]

I was more or less in the same position as you. I finally decided that I would not take the risk of getting 2 sdm lenses.

So I bought the 50-135 with extra warranty [Mack], I think it was for 5 years. Usually pretty cheap. The warranty cost under 50 dollars. I think they even have a 7 year warranty. Not sure how good Mack is but buys some peace of mind I guess...[At that time the Sigma 50-150 was not available so that was not an option. The 50-135 is a lovely lens and it has not had any problems. So far...]

I debated for a while regarding getting the tamron 17-50 instead of the pentax 16-50. I rented the 16-50. Really nice lens. If it were not for the sdm concerns I would have bought i. But I finally wound up getting the tamron 28-75 as I shoot a lot of amateur portraits of kids and family. That worked out for me.

[The tamron 17-50 in my research seemed to be highly rated but some complain of underexposure. Apart from that the feel and build quality of tamron vs a pentax DA* is worlds apart. The tamron looks and feels cheap but that should not matter if the images are good???]

Best of luck!

[wlachan]

I have my heart set on getting a k-5 and I thought buying the DA 16-50mm and the DA 50-135mm lenses would be nice, but I've realized that the SDM motors on these lenses fail a lot from looking at the threads here. My questions are:

What lenses would you suggest as similar lenses (with the same good optical quality) if I didn't go for the DAs?

EF-S17-55/2.8 & EF70-210/4L IS (or f2.8 II). Okay these are Canon lenses but they are the best if zooms are what you want. I recommend LIMITED primes highly, but avoid any DA zooms, * or not.

Most of the complaints about SDM failures seem to be from 2007-2009. Are the new lenses from 2009-2010 failing as well? I am hoping that maybe Pentax fixed the QA/design issues in the recent lenses?

New stories keep poping up.

Does anyone know if Pentax officially acknowledged fixing these issues?
Thanks!

Nope. The problem never exists. LOL.

[mel]

I bought the Sigma 17-50/2.8 when my DA*16-50 became unreliable. I've had it for a few weeks now and am quite happy with it.

[twitch]

The new Sigma 17-50 HSM seems to be getting even higher praise than the Tam 17-50, but it is bigger both in size and price tag.

[Ash]

As with this thread: Ahhh...the DA* dilemma.. - PentaxForums.com the alternatives are not weather resistant. Nevertheless, both the Sigma and Tamron counterparts are reasonably good optically to consider. I loved the DA* 16-50 and 50-135 optically and was always torn to let them go, but the focusing was not up to speed to my liking, and they seemed to struggle more in low light focusing than with screwdriven lenses. But they were worth it for most of my photography when I had them.

[pop4]

I have my heart set on getting a k-5 and I thought buying the DA 16-50mm and the DA 50-135mm lenses would be nice, but I've realized that the SDM motors on these lenses fail a lot from looking at the threads here. My questions are:

• What lenses would you suggest as similar lenses (with the same good optical quality) if I didn't go for the DAs?

I'd suggest the Sigma 17-50mm F2.8 HSM and either the Sigma 50-150mm F2.8 HSM II (which may be getting hard to find) or Sigma 70-200mm F2.8 HSM II (maybe even the 70-200 F2.8 OS HSM version if you want to spend the $$$), depending on your focal length needs. All have HSM, which is Sigma's version of Canon's USM, Nikon's SWM and Pentax's SDM, which means fast and quiet focusing, and have fast, constant f/2.8 max apertures.

If quiet focusing isn't as much of an issue for you, then other options include the Tamron 17-50mm F2.8 and Tamron 70-200mm F2.8.

Disclosure: I own the Sigma 17-50/2.8 HSM and 70-200/2.8 HSM II

• Does anyone know if Pentax officially acknowledged fixing these issues?

IMHO, you have a bigger chance of squeezing blood out of a stone than getting Pentax to officially acknowledge an issue with SDM.

[thejediknight]

Thanks for all the input guys! I am going to research all the lenses mentioned and make a choice! :-)

[simico]

Sigma used to make a 50-150 that seems to get a lot of praise. I've never owned one, so I can't say for certain if the IQ is as good as the DA*

In my experience it's practically as good as 50-135, the differences are so subtle in real life images that they doesn't really matter - the photographer and the PP applied makes far bigger difference than the lenses.

[dgaies]

In my experience it's practically as good as 50-135, the differences are so subtle in real life images that they doesn't really matter - the photographer and the PP applied makes far bigger difference than the lenses.

And that's pretty much what I assumed as I've never really heard anything bad about the sigma 50-150.

[thejediknight]

Guys, I decided to buy the Pentax DA lenses. But I also bought the MACK 7 year extended warranty with it just in case the SDM motors fail. And since I am not a professional, I guess the lack of a lens during repair time is an acceptable trade off for having good weather sealed glass. I hope atleast :-). Thanks for all your input.

[Rondec]

I think you will be satisfied. Enjoy shooting and don't worry too much.

[robgo2]

I have no doubt whatsoever that SDM failure is a bonafide issue with Pentax lenses, but none of us knows its actual rate of occurrence. Is it 2%, 6%, 10%? I have no idea. But one thing we do know is that people who experience SDM failure are moderately likely to complain about it loudly and repeatedly on forums such as this, which can create an impression that it is more common than it actually is.

My sense is that there were many more failure reports in the first year after the lenses were introduced. If true, this suggests that Pentax has made some adjustments in the fabrication process without any public announcement. It would be very foolish of them not to do so and to continue selling products with a high failure rate. However, if there continues to be an inordinate number of failures in recently produced batches, it would suggest a fundamental design flaw, something that I do not rule out.

I do think that purchasing an extended warranty makes sense, given the cloud of uncertainty that hovers over the SDMs.

Rob

[Blue]

To be honest, I am surprised that someone hasn't sued the pants off of those Hoya boys over the way they handled this. My experience with Nikon was a lot different. The replaced a sensor in a camera that was 2 years out of warranty because it had been on recall. All I was out of was shipping one way.