[ruoyun.huang]

thinking of getting a 16-50 or 20-40. SDM failure the biggest fear ... Hope the issue has been fixed?

Any chance we can start another poll in the forum regarding recent purchased lens?

[crewl1]

The 20-40 does not use SDM, it is DC which has been working reliably in the DA18-135 with no issues reported that I know of.

[jrpower10]

I bought a DA 50-135 new 5 years ago and never had a SDM problem. Bought a DA 16-50 a year ago 2nd hand and neither I or the forum member I bought it from have had an issue. (of course, I'm beating on my wood desk as we speak )

[normhead]

Sooner or later, every SDM motor will fail. It may not be for 30 years, but, it will happen. I still use an old Rockwell drill I bought in 74, and used for 6 years industrially. So they can last a long time. But will they last as long as A lenses? It's unlikely. If that's a concern, buy A lenses. As for SDM lenses, mine will fail, but I'm way too old to worry about it. I'll fail first.

[Rnovo]

thinking of getting a 16-50 or 20-40. SDM failure the biggest fear ... Hope the issue has been fixed?

Any chance we can start another poll in the forum regarding recent purchased lens?

I just wrote a report on my 16-50mm in the lens data base. You may want to look at it before you do anything...and check all the other reports there! The problem is that it is a good all around lens - not a "pro level" lens, but a reasonable fast one with f2.8 and good IQ. The SDM motor seems to have been improved lately (no conformations on this...) but I would be extremely cautious and maybe you want to seriously consider the Tamron 17-50mm as an alternative or any other like the Sigma one, I'm not familiar with them. Anything but that 16-50mm for one specific reason: in case you run into a problem like me, you're finished, you will not get any sympathy from Pentax... You spent big bucks for a dud and you are stuck with it, using it in manual or as a screw drive, because nobody will ever buy it from you. I may point out also that its not only the SDM... it's the hardware: gears, lens supports, everything in that lens has gone wrong in mine, at least. Just my 2 cents and I'm not a happy camper after being a Pentax user since 1978.
One last word before I cool off, my 50-135mm packed it in too, the SDM was changed as well as "lens carriage system" or whatever...$485 to fix. So here we go again...!!!
Actually, I'm discovering the beauty of my old Takumars. In fact, I don't need those fancy lenses and I'm getting back into the old "hyperfocal settings" that are still valid today... without loosing out in any assignments. GO MANUAL...

[ruoyun.huang]

Sooner or later, every SDM motor will fail. It may not be for 30 years, but, it will happen. I still use an old Rockwell drill I bought in 74, and used for 6 years industrially. So they can last a long time. But will they last as long as A lenses? It's unlikely. If that's a concern, buy A lenses. As for SDM lenses, mine will fail, but I'm way too old to worry about it. I'll fail first.

this comment can be applied to anything, apparently people are looking for something that last for reasonable amount of time, not like some 16-50 fails in a few years

---------- Post added 05-15-2015 at 10:57 AM ----------

The 20-40 does not use SDM, it is DC which has been working reliably in the DA18-135 with no issues reported that I know of.

yes, 20-40 does not have sdm.

I wouldn't consider 20-40 at all if there is no SDM issue on 16-50, because I do need that extra range more.

[crewl1]

When my SDM 50-135 started having issues I had it converted to screw drive.
That could be an option for a 16-50 if you really want one otherwise.

[K57XR]

What about the new 16-85?

[Rnovo]

What about the new 16-85?

Yes, but it's only f3.5-5.6 and not f2.8...that's the problem. Not fast enough.

[normhead]

this comment can be applied to anything, apparently people are looking for something that last for reasonable amount of time, not like some 16-50 fails in a few years

Naw, my old Eastwing Hammer will be good until someone abuses it, my chisels will be good until I sharpen them down so much there's nothing left, there are a lot of things that will last hundreds of years, and I own some of them. My smoothing plane was patented in 1904 and it's as good today as the day it was made. And anything manufactured with more than a few moving parts will eventually fail. Even with the DA 16-50 factored in, Pentax still has the best frequency of repair rate in the industry, and part of that is so many of their current lenses are still screw drive. If you go electric drive, you have failures, and I don't care who you are. It's not a law that applies to just Pentax, it's a law that applies to everyone. Nikon, Canon, Sony, whoever. Time for folks to stop jumping on SDM as if it has some special place in history.

[Rnovo]

I totally agree, until something else fails in the lens and then it won't make a difference. That's what happened to mine.

[aleonx3]

I totally agree, until something else fails in the lens and then it won't make a difference. That's what happened to mine.

May be you are just unlucky to get a bad copy of the lens..., if I remember correctly, the initial production batch of the SDM lenses uses sub-par parts according to the support team here in Canada - which had been corrected soon after that.

[Rnovo]

May be you are just unlucky to get a bad copy of the lens..., if I remember correctly, the initial production batch of the SDM lenses uses sub-par parts according to the support team here in Canada - which had been corrected soon after that.

Thanks aleonx3, I don't know if that makes me feel any better but confirms that the least they can do is replace it... I'll just bite the bullet on my 50-135mm $485 repair and deactivate its SDM.

[normhead]

Thanks aleonx3, I don't know if that makes me feel any better but confirms that the least they can do is replace it... I'll just bite the bullet on my 50-135mm $485 repair and deactivate its SDM.

I have to say, I wish Pentax would have covered that and given you a decent lens. And I'd happily pay the extra 10-20$ it would probably cost, added on to each lens, to replace the lemons with new glass. This is the part of corporate strategy I don't understand. How is it worth their while to treat their own customers poorly? We regularly shop at an outdoor store for gear, when there is a cheaper cut rate store across the street. Because the better store replaces broken gear beyond the manufacturer's warranty. If a tent or airmat breaks in an unreasonable amount of time they replace it over the counter. Selling me an extended warranty that makes the warranty company a lot of money is hardly fair practice.

[aleonx3]

Thanks aleonx3, I don't know if that makes me feel any better but confirms that the least they can do is replace it... I'll just bite the bullet on my 50-135mm $485 repair and deactivate its SDM.

Actually, my 16-50 copy belongs to the early batches, Pentax repair shop in Canada just replaced the lens with another copy after I complained about inconsistent metering (may/not be SDM related) - different serial number. It has been working since that day with no SDM issue.

---------- Post added 05-16-2015 at 09:55 AM ----------

I have to say, I wish Pentax would have covered that and given you a decent lens. And I'd happily pay the extra 10-20$ it would probably cost, added on to each lens, to replace the lemons with new glass. This is the part of corporate strategy I don't understand. How is it worth their while to treat their own customers poorly? We regularly shop at an outdoor store for gear, when there is a cheaper cut rate store across the street. Because the better store replaces broken gear beyond the manufacturer's warranty. If a tent or airmat breaks in an unreasonable amount of time they replace it over the counter. Selling me an extended warranty that makes the warranty company a lot of money is hardly fair practice.

Norm, I agree with that, actually the damage is already done since the SDM issues with the early batches of those 16-50 and 50-135 despite the great optics in those two lenses. Those who took the lens in the early years for repair (when it was first introduced) would likely get replaced under warranty.