[jstevewhite]

the issue here is not IQ, but AF reliability. if one was looking for IQ, then that's great. but it would be insane to think that people would pay extra for a non-working AF. better make it an mf lens instead sold for half the price, that would make more sense.

personally, it's a scam. you send emails and call customer support for help and they can't even give you a decent answer. how is it difficult to answer a question with a basic Yes or No ? so you can't blame people if they start to become suspicious or uneasy with a question that is left for themselves to answer.

Your comment once again presumes that the AF is non-working on the SDM lenses, and I stand by my assertion that it's an unwarranted assertion.

What question are you talking about? I've never had any trouble with Pentax support answering questions. Or did you call them up and say "What's this I hear about a systemic problem with your SDM lenses?" If so, what do you expect them to say? The people you get on the phone are front line workers who have scripts. If you ask them a question that's not on their script, they're lost. Furthermore, they're probably directed not to alienate the customer, so they can't blow you off. This leads to circumstances where frustrated phone workers meet tenacious customers and neither is very happy with the outcome or progress of the call.

I'm just not buying the conspiracy theory, Pentaxor. I'm sorry you had trouble with your SDM lens, but I still think the vast majority of SDM owners have no such problem.

[tarsus]

Want to hear the sound of Pentax taking SDM lens money to the bank? Ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha, ha. Boycott SDM.

[qtopplings]

This thread has gone from informative to just plain silly.

[tarsus]

It's actually not funny at all. An SDM lens user that paid $900 for a DA 16-50 f2.8, for example, and then have it fail three times after the warranty runs out at $200-$300 per repair is not a joke. My problem is that I am heavily invested in Pentax, having never owned any other brand, and I cannot buy their best lenses with any sense of reliability. I shoot professionally for a newspaper and cannot afford to have a lens fail. Sure, I bring backup, but there is no way I can afford to continue to repair a lens system. I am not a Pentax basher. On the contrary, bang for the buck Pentax is the best camera value on the market. SDM lenses, however, are a flawed design which Pentax has chosen to ignore.

[jstevewhite]

It's actually not funny at all. An SDM lens user that paid $900 for a DA 16-50 f2.8, for example, and then have it fail three times after the warranty runs out at $200-$300 per repair is not a joke. My problem is that I am heavily invested in Pentax, having never owned any other brand, and I cannot buy their best lenses with any sense of reliability. I shoot professionally for a newspaper and cannot afford to have a lens fail. Sure, I bring backup, but there is no way I can afford to continue to repair a lens system. I am not a Pentax basher. On the contrary, bang for the buck Pentax is the best camera value on the market. SDM lenses, however, are a flawed design which Pentax has chosen to ignore.

I'm really very sorry for your bad luck, but I have to point out that similar stories can be found for every manufacturer and lens. This sort of thing happens with everything from cars to buildings. I'm sympathetic, really, but your bad experience doesn't mean the entire system is crap. I see your problem more as one of customer service than engineering. When I did customer support for computers, I'd have replaced (not repaired) your system the second time.

[veezchick]

I've continued researching the SDM issue since my original post and as such, am inclined to avoid SDM altogether until Pentax makes a concerted effort to first admit there is and then solve the problem. Photographically, I can't think of anything more unsettling then shelling out $$ for a lens, and then always wondering if/when it's going to work correctly. No thanks. I need confidence and piece of mind with my equipment. What's more, upon further research, it would seem the majority of users that like and stand by the SDMs, have not had/used the SDM lenses for much more than a year. I'd be curious to check back in with them in say, another year. As far as poor customer service from Pentax … unfortunately – at least in my book - that is a reflection on the entire company's attitude so that doesn't instill much confidence in their engineering either. I am pro Pentax and shoot Pentax exclusively – from my ME Super, to the ZX5Ns to the new flagship DSLRs – always more bang for the buck - but this SDM debacle has me concerned.

Additionally, upon rereading my event contracts, the DA 50-135 does not meet my focal length requirements so that lens is ruled out anyway. Although, even with the SDM issues, the DA 50-135 raves had me goin’ there for a bit.

As for Tamron, I have their “award winning” 18-250 and it’s crap. So disappointed (subject of another post a couple years back). I’ve since learned to get the best performance out of it that I can and it’s still not there for me. That, plus the abundance of poor reviews on the fast Tamron lenses in the focal ranges I want, have turned me off of Tamron completely.

So … in the end, it’s the Sigmas – 10-20mm f/3.5, 24-70mm f/2.8 and 70-200 f/2.8. And while I’m at it, I’ll get another 540 flash and some long overdue accessories. And then I'll be stone cold broke 'til I get a lot of gigs.

I appreciate everyone’s feedback. Great crew, here. Cheers.

[jstevewhite]

I've continued researching the SDM issue since my original post and as such, am inclined to avoid SDM altogether until Pentax makes a concerted effort to first admit there is and then solve the problem. Photographically, I can't think of anything more unsettling then shelling out $$ for a lens, and then always wondering if/when it's going to work correctly. No thanks. I need confidence and piece of mind with my equipment. What's more, upon further research, it would seem the majority of users that like and stand by the SDMs, have not had/used the SDM lenses for much more than a year. I'd be curious to check back in with them in say, another year. As far as poor customer service from Pentax … unfortunately – at least in my book - that is a reflection on the entire company's attitude so that doesn't instill much confidence in their engineering either. I am pro Pentax and shoot Pentax exclusively – from my ME Super, to the ZX5Ns to the new flagship DSLRs – always more bang for the buck - but this SDM debacle has me concerned.

Additionally, upon rereading my event contracts, the DA 50-135 does not meet my focal length requirements so that lens is ruled out anyway. Although, even with the SDM issues, the DA 50-135 raves had me goin’ there for a bit.

As for Tamron, I have their “award winning” 18-250 and it’s crap. So disappointed (subject of another post a couple years back). I’ve since learned to get the best performance out of it that I can and it’s still not there for me. That, plus the abundance of poor reviews on the fast Tamron lenses in the focal ranges I want, have turned me off of Tamron completely.

So … in the end, it’s the Sigmas – 10-20mm f/3.5, 24-70mm f/2.8 and 70-200 f/2.8. And while I’m at it, I’ll get another 540 flash and some long overdue accessories. And then I'll be stone cold broke 'til I get a lot of gigs.

I appreciate everyone’s feedback. Great crew, here. Cheers.

FWIW, I bought my 50-135 and 16-50 in (edit:March of) 2009. No issues. Of course, it's your cash, so ...

I would say this: If you want an eye opening experience, google "USM failure" (canon), "HSM failure" (Sigma), and "SDM failure" (pentax) - and then whatever Nikon calls theirs. There are many people who are just as convinced that the others are failed designs, too.

Yeah, I've not found *any* of the 18-2xx lenses that meet my ... 'needs'. I've got the Sigma 18-200 currently, and as long as I remember that I bought it *instead* of a P&S camera, it's fairly satisfying, but when I start thinking I can take real pictures with it (beyond snapshots) I find myself ready to toss it out the window. To be fair, I think the "award winning quality" of the Tamron is just "in comparison to other 18--2xx zooms".

[Eruditass]

I've continued researching the SDM issue since my original post and as such, am inclined to avoid SDM altogether until Pentax makes a concerted effort to first admit there is and then solve the problem. Photographically, I can't think of anything more unsettling then shelling out $$ for a lens, and then always wondering if/when it's going to work correctly. No thanks. I need confidence and piece of mind with my equipment. What's more, upon further research, it would seem the majority of users that like and stand by the SDMs, have not had/used the SDM lenses for much more than a year. I'd be curious to check back in with them in say, another year. As far as poor customer service from Pentax … unfortunately – at least in my book - that is a reflection on the entire company's attitude so that doesn't instill much confidence in their engineering either. I am pro Pentax and shoot Pentax exclusively – from my ME Super, to the ZX5Ns to the new flagship DSLRs – always more bang for the buck - but this SDM debacle has me concerned.

Agreed, I was thining about buying a couple of them for my Alaska trip but now I'm having second thoughts.

Additionally, upon rereading my event contracts, the DA 50-135 does not meet my focal length requirements so that lens is ruled out anyway. Although, even with the SDM issues, the DA 50-135 raves had me goin’ there for a bit.

As for Tamron, I have their “award winning” 18-250 and it’s crap. So disappointed (subject of another post a couple years back). I’ve since learned to get the best performance out of it that I can and it’s still not there for me. That, plus the abundance of poor reviews on the fast Tamron lenses in the focal ranges I want, have turned me off of Tamron completely.

Why would you compare a superzoom with professional glass? Completely different league...

So … in the end, it’s the Sigmas – 10-20mm f/3.5, 24-70mm f/2.8 and 70-200 f/2.8. And while I’m at it, I’ll get another 540 flash and some long overdue accessories. And then I'll be stone cold broke 'til I get a lot of gigs.

From what I have seen, the Tamron 70-200 f/2.8 bests the HSM versions of Sigma 70-200mm in IQ, but not focusing speed (or sound), and the Tamron 28-75mm is a bit better than the Sigma 24-70mm, but pretty similar. Sigma 10-20mm is supposedly significantly better than the Tamron 10-24mm.

All in all, depends on specific lenses.

[veezchick]

If you want an eye opening experience, google "USM failure" (canon), "HSM failure" (Sigma), and "SDM failure" (pentax) - and then whatever Nikon calls theirs. There are many people who are just as convinced that the others are failed designs, too.

I did that. Sigma HSM failure vs. Pentax SDM failure is about 5.5:1 according to Google “hits.” But since it’s probably fair to say that less than 1 in 5.5 shooters use Pentax, the numbers would be in Sigma’s favor.

Why would you compare a superzoom with professional glass? Completely different league...

Not comparing, per se. Just don't like anything about my Tamron 18-250 so it doesn’t instill much confidence in any of their products. Also, the reviews I’ve seen of the fast Tamron glass were not so great. The slow/noisy Tamron AF is a turnoff. Conversely, I like my low-end Pentax lenses okay and hoped to buy their faster DA/DA* offerings. That is, until I researched things further.

I really want to want Pentax or Tamron – it’d save me a lot of cash – but in the end, I want dependability, good reach, really good IQ, fast/quiet AF and confidence in the product. If paying 2 to 3 times more for the Sigma array does that for me, oh well (heavy sigh). I don’t want a “great lens for the money” … I just want great lenses – well ... the best I can afford for now, anyway.

[jstevewhite]

I did that. Sigma HSM failure vs. Pentax SDM failure is about 5.5:1 according to Google “hits.” But since it’s probably fair to say that less than 1 in 5.5 shooters use Pentax, the numbers would be in Sigma’s favor.

I wasn't trying to suggest that "HSM is worse than SDM", just that all makers and many designs have their 'failure mythology'. I believe both are probably reliable for the most part. When you build the motor into the lens you increase your individual chances of experiencing a failure - 1 photog*n cams (usuall 1 or 2), or 1 photog*n+ lenses. (usually many more lenses than cameras)

[Tord]

Why not:
Sigma 10-20 f/3.5
Sigma 17-50 f/2.8 OS
Sigma 50-150 f/2.8

*Putting on flame suit*
I would take the Sigma 17-50 f/2.8 OS over the Pentax 16-50 unless I just had to have weather sealing. The Sigma is a better lens.

I would take the Tamron 70-200 over the Sigma. The Pentax 60-250 f/4 is an excellent lens, but it is 2x the price of the Tamaron.

Before you buy a 30mm prime check out the performance of the Sigma 17-50mm f/2.8 at 30mm. Sigma 17-50 mm f/2.8 EX DC OS HSM review - Image resolution - Lenstip.com
It is a very good lens at that focal length and compares very well against primes.

I would also take the Tamron any day! How does this SDM problem show itself?!

[northcoastgreg]

There is a certain image presence that no digital processing can add. Some lenses have it, others don't. Nearly all the Pentax primes that I've ever used do. Digital processing can compensate for some of that, but, for instance, you'll never make an image from a Sigma zoom look like an image from, say, the Pentax 100mm f2.8 Macro. Image processing is a very broad brush, and the differences between lenses can be very fine.

I have found this to be true in general of Pentax primes and even the better sort of Pentax zooms. It's might be a consequence of the Pentax coatings, which I suspect are still better than everyone else's (except Zeiss). Coatings affect light transmission, but they don't affect light transmission evenly: some parts of the spectrum may be favored over others. The Pentax DA 18-55, for example, allows only about 65% of the violet end of the spectrum through, which means less color information is reaching the lens compared to glass that is better in this respect. Less information means less to work with in post; which may at least partially explain why you can't make an image taken with a Sigma or Tamron (or Canon or Nikon) lens look like an image from one of the best Pentax (or Zeiss) primes and zooms.

[civiletti]

… in the end, it’s the Sigmas – 10-20mm f/3.5, 24-70mm f/2.8 and 70-200 f/2.8.

I like the sigma 8-16 and 17-50.

[Boris]

I would say this: If you want an eye opening experience, google "USM failure" (canon), "HSM failure" (Sigma), and "SDM failure" (pentax) - and then whatever Nikon calls theirs. There are many people who are just as convinced that the others are failed designs, too.

Indeed. And then on a personal level, when your specific lens or camera body breaks, it is going to boil down to the very dealership or laboratory or a person who'd be servicing your gear. That varies wildly from country to country.

[ManuH]

I'm adding my 2 cents to this thread:

I have the DA* 50-135mm since the summer of 2008. Thousands of pictures with K10D, K20D, K-7 and K-5. Still working perfectly. Last week my heart stopped when it stopped focusing. I tried to turn on and off the camera to no avail. After a while I just realized that my AF/MF switch on the lens was slightly off position. I was relieved. But after reading so many complaints about SDM failures on this forum I thought it was my turn. But I really which that Pentax give us the option to use screw-drive when SDM fails, the hardware is there, why would I have to buy an old *ist D/DS/DL to make my DA* lens focus again?

About Sigma lenses:
I try to avoid them whenever I can, but I cannot always because they have some unique offering like the 8-16mm and the 30mm f/1.4 I just bought. While the 30mm is OK (bought used from this forum) I already have to return the 8-16 because it hunts and hunts and hunts for no apparent reason. Last year I returned a 70-200mm HSM II because out of the box the rear element was scratched and the lens front focused like crazy. Sigma has a bad reliability reputation, Lensrentals decided to ditch them completely because of that.

The other things I don't like is they use bogus lens ID. That fools Lightroom and the camera. If you have all Sigma lenses and need AF calibration you risk to have 2 or 3 lenses sharing the same ID. LR doesn't recognize the lens and cannot apply automatically the profile. Tamron lenses don't do that. Compatibility issues can arise with new features (no CD-AF, don't expect the camera to auto correct CA/distortion on Sigma lenses).

On the positive side, here in Canada the Sigma warranty and repair are good. They are handled by Gentec which does a very good job. Note that Pentax Canada is quite good too (and they have 2 years warranty here).

HSM seems also faster than SDM, at least 70-200 HSM vs 50-135 SDM.

But in the end, I prefer to buy Pentax lenses whenever I can. Tamron comes second and Sigma a distant third.