[Shanti]

I'd get the 17-70 repaired. Apparently the newer SDM lenses have a better motor.

they do have a better motor now,talked with the Pentax repair in Sweden & since about 2yrs ago the SDM has been improved,so all replacements should be fine.

[sterretje]

What would be the best image quality lens in the 17-70 sort of range, for a K3? Doesn't have to be Pentax of course, but I don't want to cripple the functionality in the way it usually happens with flashguns.

No personal experience, but from reviews on the web: if you can live with 17-50, buy the Sigma 17-50. If not, buy the Sigma 17-70 Contemporary.

But for roughly $200, I would get the DA17-70 fixed.

[peterh337]

Any recommendations on the best repair option? It turns out, astonishingly, that I still have the lens under an extended warranty. This would be about the first time in the last 30 years that I have been able to claim under one of those!

[OJGoreng]

Eek!
A short while ago I took delivery of a (new) DA* 300mm. This week it developed a rattling sound and I noticed a bit of play in the focusing ring. I've mostly been using it with the 1.7x AF adapter, but I just mounted it without the adapter, and yikes.. the SDM appears to have gone dead. It won't operate on either the K-3 or K-5 (and yes, I've made sure AF is enabled on both lens and camera). I guess I have to return it for repair. What a bummer.

[Pål Jensen]

My DA* 16-50, bought in 2007, is still going fine. I think the failure rate is somewhat higher than some other lenses, but I don't think it even hit 10%. Those of us who have lenses that don't break don't make big deal threads about them, as I and some others did with the DA* 50-135 when the SDM went South. Mine was 100%. Died three times.

Mine is also bought in 2007 and works just fine...

[howieb101]

Well I have a DA*50-135mm bought in 2009 and its still going strong. The focus still has the annoying slowness that everyone talks about but the AF is still going fine.

Remember this was bought in 2009 so despite all the reported negative stories there are positives out there as well.

In fact I used this today. I should note that I am not one of those people who once a month give the lens a spin just for maintenance reasons. I can leave this lens with no use for quite extended periods, knock on wood without any issues.

Howie B

[jddwoods]

A couple of years ago I bought the 17-70 SDM (for a K5).

I read the reviews, which suggested the motor was a bit less than 100% likely to pack up than on the weatherproof alternative of a similar spec (don't recall the type but you know the one) which appeared to have a huge failure rate.

Well, just now the lens has started to get intermittent. After a bit of use it works, but sometimes you have to press the button twice to make it move.

I still have the old 16-45 and that focuses instantly.

Is it definitely the lens and, if so, what is the most cost effective way to get it fixed? There isn't a better quality lens that I can see, of that sort of focal length range.

I bought a DA 17-70 back when it was first released, may be 2008 or 2009. For years I noticed same issue you are commenting on, especially if it has not been used in a while. If it has been sitting for a month or two, it needs a couple of presses of the shutter release or even a quick shift help with the manual focus ring. So it looks like it may need a wake up after it was idle for some time. Once it gets going it works just fine, and its been like this for years, so I just accept this as a quirk of the lens. This became more noticeable after purchasing DA 21, 35 macro and 70 mm limiteds which are getting a lot more use than the 17-70 since they collectively are smaller and lighter and more versatile than the 17-70 and I do not mind swapping the primes.