Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-08-2009, 04:36 PM   #1
Senior Member




Join Date: Oct 2007
Location: Northern Virginia
Photos: Gallery
Posts: 131
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
Veteran Member




Join Date: Feb 2009
Location: Sugar Land, TX
Photos: Gallery
Posts: 684
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
Veteran Member
nostatic's Avatar

Join Date: Feb 2008
Location: socal
Photos: Gallery
Posts: 1,575
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
Veteran Member
dugrant153's Avatar

Join Date: Oct 2007
Location: Vancouver, BC
Photos: Gallery
Posts: 1,059
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
Senior Member




Join Date: Oct 2007
Location: Northern Virginia
Photos: Gallery
Posts: 131
Original Poster
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
Veteran Member
nostatic's Avatar

Join Date: Feb 2008
Location: socal
Photos: Gallery
Posts: 1,575
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
Senior Member




Join Date: Oct 2007
Location: Northern Virginia
Photos: Gallery
Posts: 131
Original Poster
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
Veteran Member
nostatic's Avatar

Join Date: Feb 2008
Location: socal
Photos: Gallery
Posts: 1,575
send them a link to the youtube video when you ship it to them
02-08-2009, 08:43 PM   #9
Site Supporter
Site Supporter




Join Date: Jul 2008
Location: Cleveland, OH, USA
Photos: Gallery
Posts: 292
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
Senior Member




Join Date: Oct 2007
Location: Northern Virginia
Photos: Gallery
Posts: 131
Original Poster
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
Veteran Member
NeverSatisfied's Avatar

Join Date: Dec 2007
Location: S.E. Michigan
Photos: Albums
Posts: 688
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
Senior Member




Join Date: Oct 2007
Location: Northern Virginia
Photos: Gallery
Posts: 131
Original Poster
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
Veteran Member




Join Date: Nov 2008
Location: New York, NY
Posts: 385
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??
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
k-mount, lens, pentax, pentax lens, slr lens

Similar Threads
Thread Thread Starter Forum Replies Last Post
Can a manual-focus lens have back focus problems? PocketPixels Pentax DSLR Discussion 33 02-13-2011 05:37 AM
k-7 auto focus problems garyk Pentax DSLR Discussion 5 10-21-2010 11:50 PM
Focus problems sherib Troubleshooting and Beginner Help 4 02-20-2010 06:37 AM
Auto focus problems??? Moorby Troubleshooting and Beginner Help 8 12-24-2009 02:24 AM
do you have focus problems with 16-45??? hll Pentax SLR Lens Discussion 25 04-11-2008 02:39 PM



All times are GMT -7. The time now is 06:40 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top