SDM 16-50 lens focusing not working

After heading out for a weekend to take some shots I have frustratingly found that my SDM 16-50 lens will only work 20 percent of the time in autofocus. I gave up in the end and took the majority of shots in manual. Coming home I have put the lens through a series of tests and it simply will not focus. The flashing indicator in the camera is blinking but not beeping to tell you that your subject is in focus and it pretty much stops working. Occasional under good lighting conditions with a flat subject the focus will work, but very occasionally. The lens is now out of warranty. What do I do??????? I have seen all over the internet that these lenses are giving all sorts of problems. What have you done Pentax!!!!!! Such a expensive lens, and you have really put pentaxusers like myself really down.

If you turn the focus ring slowly by hand, does it feel gritty?

not at all!!! To be honest this lens has probably gone through 3-400 shots and in no extreme conditions that would hinder its performance: I am sure its a dud, but I am having the feeling that the 16-50 is a dud model all together. Sure the lens quality itself is quite superior, and you can use manual focus, but half the idea of buying this lens is for the SDM motor

Try to clean the contacts on the body and the lens, that solved the problem for some users.

I was interesting in getting the DA* 16-50, but I have to admit that there's an awful lot of negative chat about this lens on the Tinterweb. Your thread is just another. Scared me off to be honest.

I'm sure there are plenty of working examples out there, but it's a lot of money to take a chance

I have tried all that, but nothing. The lens has gone schitzo. Help help help

You might be interested in this link.

I have no first hand experience of this firm but others seem to have found them helpful


Archie

If the lens was purchased through a Pentax Pro Dealer and has 2 years warranty then contact them to arrange a free repair or replacement, presuming it is less than 2 years old.

Failing that, consider taking advice from Consumer Direct if in the UK and exploring the six years you have to seek a repair/replacement on the grounds that a lens should last longer than the time you have had it.

As a last resort, paying for a repair is another option.

As regards reliability, there were early reports of SDM problems with this lens, although there were also many more people who had no problems. I wouldn't let it put me off buying one.

For the cost of repairing the DA*16-50 lens you could buy a DA 16-45. I think the 16-45 is a cracker of a lens. Having seen the quality of some of my own pictures, and moreover, others' pictures on the Pentax gallery I'm often hard pushed to see much difference between the two (with the exception of some CA maybe.

From posts on the other forum it seems Pentax are fitting a different motor into repaired lenses now so once it returns you should have no more problems.

Not helpful as such but I would still rather have the 16-50mm repaired than buy a 16-45mm .. even though I have both and use the cheaper lens 99% of the time.

I'm on my third sample of this lens, the others replaced under warranty. So far, no problems with this lens.

If you buy one because you are going to use it regularly, and it lasts 2 years, you have no worries.

If you are not going to use it regularly, why buy it? The DA 16-45mm would suit you better unless you need low light capability. In which case, the lens will be fine, but Pentax bodies are absolute pants/the pits/completely rubbish at focussing in low light. With it's on-board focus assist light, the K7 might be better than the older models.

I had a similar "no SDM AF" problem with one of my SDM lenses.

Auto-focusing the lens via the screw-drive on a body that didn't have SDM (the *istD in this case) and then putting it back on my K20D fixed the problem. It's been fine ever since.

Worth a try if you have an older body (even an old AF film body).

HTH,
R

I don't know. I am really starting to think that the SDM motor is a dud. The lens itself is amazing though. I do have to say and I have compared it to many. I read that these were a bit dodgy with some serial numbers and I am beginning to believe it. I will take in all your suggestions and see how I go. Thank you all very much for your help and feedback.

I've some luck, just checked the law about that here and it seems I've many more years then that.

They look here at the;
price
type of product
the store you bought add
what the salesman has said
what the manufacture says

Since the 16-50 isn't cheap, lenses normally last a life time and the lens comes from a specialist camera-store I'm settled.

I think it's worth checking the.

Don't forget the minimum warranty here in Europe is 2 years so don't let you throw yourself off with 1 year deals.

Can't recommend it since you can never be sure it's the SDM motor that stopped working or if there is something wrong inside the AF system.
If for example an axle is misaligned you would only wrecked the lens more.

Went away for the weekend again and tried every possible way to get my lens to wake up, but nothing. The auto focus is literally dead. What should I do?