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02-08-2009, 04:36 PM   #1
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My 16-50 focus problems

I made a video detailing the problems I have been having with my 16-50

Anyone else have similar problems??

Is this lens bad enough to send back to pentax?

YouTube - pentax 16-50 Lens test

02-08-2009, 04:50 PM   #2
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Heck yes, but how old is it? Also, don't "smash" the focus ring against the ends of the focus limit. That might break the metal that holds the ring and the body togheter and then you can't manually focus anymore. >.<
02-08-2009, 04:52 PM   #3
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Do you always spin the focus ring as hard/fast as shown in the video? Also, does it happen in decent light?
02-08-2009, 04:56 PM   #4
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Just curious which camera you're using for this test? (I didn't see the whole vid).

I had issues with the DA*16-50 (good copy) on my K100D, but when I upgraded to the K200D, the misfocusing went away.

02-08-2009, 05:02 PM   #5
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this is with a k20d. the lens is about 6 months old. and I was spinning the focus ring fast because it usually "locks" or whatever it is doing and if you spin it fast you can get it to break lose sometimes. (although i almost never manual focus or quick shift focus anyway) I have only had to with the 16-50 because of the poor AF performance.
02-08-2009, 05:08 PM   #6
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QuoteOriginally posted by qksilver Quote
this is with a k20d. the lens is about 6 months old. and I was spinning the focus ring fast because it usually "locks" or whatever it is doing and if you spin it fast you can get it to break lose sometimes. (although i almost never manual focus or quick shift focus anyway) I have only had to with the 16-50 because of the poor AF performance.
The first time it "locked" why didn't you send it off for repair?!?
02-08-2009, 05:12 PM   #7
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QuoteOriginally posted by nostatic Quote
The first time it "locked" why didn't you send it off for repair?!?
It is still under warrany, It is just a pain in the ass to send stuff to pentax. My concern is that is is inconsistent, sometimes it works fine. So my concern is that I will send it to pentax, it will work fine for them and they ship it back to me and say its fine.
02-08-2009, 05:17 PM   #8
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send them a link to the youtube video when you ship it to them

02-08-2009, 08:43 PM   #9
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Hi,
I think there are 2 possibilities:
1 - the lens is busted and you better send it for repair or exchange
2 - the exact focus point is on the edge: sometimes it's on that phone, sometimes it's on the background wall; also, be aware that 50mm on different lenses could be 49mm or 51mm or whatever focal length this particular lens is built for; btw, I didn't see one of those red focus confirmation squares on that video.
I'd say, re-do the test with nice focusing target, eliminate any possible errors.
Good luck,
02-08-2009, 09:50 PM   #10
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the camera was on a tripod using center focus. i made sure the focus point right on the speaker. This is not a problem i get when only doing a test. whenever I use the lens during regular shooting it fails to confirm focus about 50% of the time.
02-09-2009, 09:32 AM   #11
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Similar Problem with DA*50-135

Qksilver,
I checked out your YouTube video- although nowhere near as bad or as consistent, my 50-135 is doing the same thing. The one thing I especially picked up on was the squeaking sound your 16-50 is making. The 50-135 is starting to make the same noise. I'm sending the lens in to Pentax -today- BUT, it's a month and a half past warranty. Optically it still makes great images, but...

When I first bought my K10D, over a year ago, I was really interested in other options in lenses. The Sigma 50-150/2.8 sounded interesting, but not available for Pentax. The Tamron 17-50/2.8 had a great reputation, but not available for Pentax. So I spent big $$ for Pentax's two top of the line zooms, the DA*16-50 and DA*50-135. The 16-50 was one of the bad ones and had to be replaced under warranty (the replacement -IS- a very good copy though). And now the 50-135 is going bad. Ironically, those Sigma and Tamron lenses I was looking into before are NOW available for Pentax, too.

I hope it doesn't cost me an arm and a leg to get this lens fixed.
Paul
02-09-2009, 10:43 AM   #12
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I feel your pain, the SDM on my first 50-135 failed after a year. It was replaced under warranty just in time. I am concerned about the lifetime of the sdm system vs the screw mount. It seems like the screw mount might be a more long lasting design
03-12-2009, 12:16 PM   #13
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I have a 50-135mm coming in, it will my first SDM lens. I just wonder how widespread this AF issue is with SDM lens??
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