Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-07-2014, 09:13 PM   #1
Junior Member
fewing1's Avatar

Join Date: Feb 2011
Location: Alberta
Photos: Albums
Posts: 37
Questions about DA* 16-50

Hi all,


I purchased a used DA*16-50 to use on my K30 and the autofocus doesn't seem to be working.. I was wondering if someone could answer some questions about this lens. When I have it on full auto, should I not hear/feel it trying to focus? With the quick shift is there a wrong way to turn the focus ring. I thought I understood that you press the shutter half way to have it auto focus and then when its locked you can turn the focus ring to fine tune it(making sure the shutter release is kept half way down) Can it be turned all the way around or should it be turned all the way around? should I be rotating it in either clockwise or counter clockwise to focus? The copy I have seems to almost drag if I have it on auto or manual. The focus ring doesn't seem freely move as some of my other lenses. It seems to work fine on manual focus. I have returned it to the seller, but I am just wondering for the little bit I saved on price if I should just bite the bullet and buy new and maybe have better luck?

08-07-2014, 09:55 PM   #2
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
QuoteOriginally posted by fewing1 Quote
d the autofocus doesn't seem to be working.. I was wondering if someone could answer some questions about this lens. When I have it on full auto, should I not hear/feel it trying to focus?
Maybe, it is very quiet so maybe not. But you should definitely see it move into focus.
QuoteOriginally posted by fewing1 Quote
With the quick shift is there a wrong way to turn the focus ring. I thought I understood that you press the shutter half way to have it auto focus and then when its locked you can turn the focus ring to fine tune it(making sure the shutter release is kept half way down)
No, there is no wrong way. It goes either direction.
QuoteOriginally posted by fewing1 Quote
Can it be turned all the way around or should it be turned all the way around? should I be rotating it in either clockwise or counter clockwise to focus?
It goes all the way around, though that also means you can turn the ring further than infinity, but of course the lens stops there, just the ring continues to turn, there is no 'stop' as on manual lenses.
QuoteOriginally posted by fewing1 Quote
The copy I have seems to almost drag if I have it on auto or manual. The focus ring doesn't seem freely move as some of my other lenses.
That seems odd, mine has no drag at all, just butter smooth. Though you should feel the slight 'stop' when it comes to the end of the focus range. Just a little click and then the ring continues to turn. Watch the distance scale as you turn and you can see it hits the stop and just keeps going.

I have bought most of my lenses used, but I did buy the DA*16-50 new. And ended up with a bad SDM motor that required repair. Still after 10,000 images with it I am not complaining. But at this point I would not buy one used, only new with a warranty. Just my opinion.
08-07-2014, 09:56 PM   #3
Loyal Site Supporter
Loyal Site Supporter
blackcloudbrew's Avatar

Join Date: Mar 2009
Location: Cotati, California USA
Photos: Gallery | Albums
Posts: 4,459
I suspect the SDM autofocus system has failed.
08-08-2014, 12:23 AM   #4
Senior Member
mythguy9's Avatar

Join Date: Jun 2012
Photos: Albums
Posts: 276
QuoteOriginally posted by jatrax Quote
But at this point I would not buy one used, only new with a warranty. Just my opinion.
Agree. I read a lot of forum threads before buying my copy new, mainly because of the SDM issues in older copies.

08-08-2014, 12:30 AM   #5
Pentaxian
Franc's Avatar

Join Date: Jan 2010
Location: Hoevelaken
Photos: Gallery
Posts: 1,211
do you have another SDM lens? On my K7 the SDM motor inside the camera was broken so SDM lenses didn't work.
08-08-2014, 08:09 AM   #6
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
QuoteOriginally posted by Franc Quote
On my K7 the SDM motor inside the camera was broken so SDM lenses didn't work.
Hmm, there is no SDM motor in the camera, it is in the lens.
08-08-2014, 10:25 AM   #7
Junior Member
fewing1's Avatar

Join Date: Feb 2011
Location: Alberta
Photos: Albums
Posts: 37
Original Poster
Thanks for the replies, thought I was perhaps losing my mind. and no this is the first quick shift lens that I have purchased, so I didn't have anything to reference it to.

08-08-2014, 11:47 AM   #8
Pentaxian
Franc's Avatar

Join Date: Jan 2010
Location: Hoevelaken
Photos: Gallery
Posts: 1,211
QuoteOriginally posted by jatrax Quote
Hmm, there is no SDM motor in the camera, it is in the lens.
there is that thing then that activates the lens SDM. On my K7 repair bill it said SDM
08-08-2014, 12:01 PM   #9
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
QuoteOriginally posted by Franc Quote
there is that thing then that activates the lens SDM. On my K7 repair bill it said SDM
SDM contacts maybe? Those are the little brass contacts that used to be used for the powerzoom lenses. They now provide the power for the SDM motor in the lens.
08-12-2014, 12:50 AM   #10
Pentaxian
Franc's Avatar

Join Date: Jan 2010
Location: Hoevelaken
Photos: Gallery
Posts: 1,211
it was the complete unit and not just the contacts
08-12-2014, 09:50 AM   #11
Veteran Member




Join Date: Feb 2011
Posts: 4,873
QuoteOriginally posted by fewing1 Quote
Hi all,


I purchased a used DA*16-50 to use on my K30 and the autofocus doesn't seem to be working.. I was wondering if someone could answer some questions about this lens. When I have it on full auto, should I not hear/feel it trying to focus? With the quick shift is there a wrong way to turn the focus ring. I thought I understood that you press the shutter half way to have it auto focus and then when its locked you can turn the focus ring to fine tune it(making sure the shutter release is kept half way down) Can it be turned all the way around or should it be turned all the way around? should I be rotating it in either clockwise or counter clockwise to focus? The copy I have seems to almost drag if I have it on auto or manual. The focus ring doesn't seem freely move as some of my other lenses. It seems to work fine on manual focus. I have returned it to the seller, but I am just wondering for the little bit I saved on price if I should just bite the bullet and buy new and maybe have better luck?
Likely an SDM failure, common on the early 16-50's.

There's no wrong way to eat a Reese's. I mean, to turn a focus ring.
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!
auto, camera, focus, half, pentax help, photography, questions, questions about da*, shutter
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
DA* 16-50 owners, question about your aperture blades when open jotarou1 Pentax SLR Lens Discussion 6 06-25-2014 12:50 PM
pentax da 16-45 vs 16-50 da* for K5? gf1 Pentax SLR Lens Discussion 18 11-16-2013 10:14 AM
Shootout #2 - DA 15 Ltd / Tamron 17-50 @17 / DA* 16-50 @16 / Sigma 10-20 @16 EarlVonTapia Pentax SLR Lens Discussion 4 06-23-2013 10:17 PM
Pentax 16-50 F2.8 vs Tamron 17-50 F2.8 - Questions about size/weight ? photoleet Pentax SLR Lens Discussion 6 03-04-2013 10:54 PM
Questions regarding BF/FF and the DA* 16-50 PentaxScott Pentax SLR Lens Discussion 8 05-06-2008 08:30 AM



All times are GMT -7. The time now is 12:57 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