[jeffryscott]

I'm close to purchasing a 16-50 and 50-135 (or 60-250) and am a little nervous about the potential SDM issues. Is it worth the extra $200 to buy the 16-50 new at B&H for the warranty and hope that a late model has the rumored improved SDM.

Or, do I go with KEH, which has the 16-50 in the 750-800 range with a six month warranty and an unknown age/history (or buy on the forums for a similar price with no warranty.)

Thanks,

Jeff

(I want to stick with Pentax glass for the WR and consistent color rendition)

[jatrax]

That will be a hard question to answer. Early on the 16-50 in particular had many reported SDM issues. However, AFAIK no discernible pattern was found despite the serial number database. Some had multiple failures over a short time, some have never failed. The 50-135 seemed to have less issues reported, (or maybe there were fewer in service) and I can only remember a very few 60-250's reported.

Check the serial number database to see the information there: Pentax Serial Number Database - PentaxForums.com

I just bought a used 60-250 from a member here so I guess that illustrates my confidence, But if buying used do keep in mind the potential you will need to send it in for repair at some point. That might also be true with a new one but hopefully it would be under warranty.

[jeffryscott]

I'm not too worried about either the 50-135 or 60-250. It seems as though the 16-50 is more prone to failure so that is the one I'm concerned with.

[siamthai]

I would go for the new lens if it's only $200 more than the used one (and the 60-250mm if you can afford it, it's heavy but really the best zoom in the DA* series).

[panoguy]

I'm close to purchasing a 16-50 and 50-135 (or 60-250) and am a little nervous about the potential SDM issues. Is it worth the extra $200 to buy the 16-50 new at B&H for the warranty and hope that a late model has the rumored improved SDM.

Unless you really need a quiet DA*16-50, there is also this "solution" to SDM problems (which I can attest works very well, and is as reliable as any other screwdriven lens):
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/208353-how-dea...m-f-2-8-a.html

Of course, a warranty is always welcome, but if the SDM did fail and you send it in, you'd be without your lens for 2+ weeks (and pretty P.O.'d judging by the usual angry reactions around here)...

[Adam]

I'm close to purchasing a 16-50 and 50-135 (or 60-250) and am a little nervous about the potential SDM issues. Is it worth the extra $200 to buy the 16-50 new at B&H for the warranty and hope that a late model has the rumored improved SDM.

Or, do I go with KEH, which has the 16-50 in the 750-800 range with a six month warranty and an unknown age/history (or buy on the forums for a similar price with no warranty.)

Thanks,

Jeff

(I want to stick with Pentax glass for the WR and consistent color rendition)

The currently price at B&H is low ($969), so I would just grab a new one, as the SDM issue was supposedly fixed last year. Unless you really need the weather sealing, though, I'd recommend strongly considering the Sigma 17-50mm as an alternative.

[Canada_Rockies]

My DA* 16-50 has had zero issues, and is an early model. The lens is about the best walk around lens I've ever had used on my K10D, bar the FA 24-90 on MZ-S. I had a DA*50-135 with SDM that failed three times, and got rid of it because that focal range is very reliant on AF. However, the range of the 16-50 and what I use it for would not bother me a heck of a lot to use it in manual focus if the SDM were to fail. Why couldn't the 16-50 AF fail instead of the 50-135??????

I highly recommend DxO Pro with the 16-50. It improves the quality of the images very nicely all on its own. Best $150 improvement to a series of lenses I ever made.