Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-02-2012, 06:46 AM   #1
New Member




Join Date: Jul 2012
Posts: 6
Problem with swithching Simga lens MF to AF

I have Pentax k-x camera and Sigma 10-20mm f4-5,6 lens. When I mount lens on camera and turn it on, camera shows "Input focal length" and on display is MF icon, but when I switch to AF display still shows MF and lens works as in MF mode, AF doesn't work. I have checked all setting but cant find solution. AF does work with kit lens. I have cleaned contact etc, so I'm asking for help!
I bought Sigma lens 3 month ago and it had no problems till now.

ps. sorry about my english... it's not my native


Last edited by LenorAD; 07-02-2012 at 06:47 AM. Reason: had more to add
07-02-2012, 07:52 AM   #2
Site Supporter
Site Supporter
Pauld's Avatar

Join Date: Nov 2009
Location: Calgary, Alberta
Photos: Gallery | Albums
Posts: 507
I am having the exact same problem with 2 of my Sigma lenses and I still have no idea what the problem is.
07-02-2012, 07:55 AM   #3
Pentaxian
JinDesu's Avatar

Join Date: Jun 2011
Location: New York City
Photos: Gallery
Posts: 5,626
I had that problem with my Sigma 10-20 F4-5.6. The issue seemed to be that I did not mount it fully in place whenever that happened. A slight tightening twist, and the lens would work perfectly fine.
07-02-2012, 09:22 AM   #4
New Member




Join Date: Jul 2012
Posts: 6
Original Poster
I tried to tighten the twist, but it still don't work as it should. I guess I have to contact with store where I bought it. Does this problem counts as warranty problem?

07-02-2012, 09:23 AM   #5
New Member




Join Date: Jul 2012
Posts: 6
Original Poster
Is it actually a Pentax or Sigma problem... hmm?
07-02-2012, 11:49 AM   #6
Veteran Member




Join Date: Jan 2010
Location: Vancouver, BC
Posts: 1,421
QuoteOriginally posted by LenorAD Quote
Is it actually a Pentax or Sigma problem... hmm?
I would say it's the lens, but you can make certain if the shop where you've bought the lens from try it out on another Pentax DSLR. I have the same lens and I had no trouble with AF on a K100DSuper, K10D and K20D.
07-02-2012, 11:53 AM   #7
Pentaxian
JinDesu's Avatar

Join Date: Jun 2011
Location: New York City
Photos: Gallery
Posts: 5,626
QuoteOriginally posted by LenorAD Quote
Is it actually a Pentax or Sigma problem... hmm?
If you have other lenses that are working fine with the camera, then it's the lens problem.

I would say it counts as a manufacturing defect, and would qualify under warranty.
07-02-2012, 12:06 PM   #8
New Member




Join Date: Jul 2012
Posts: 6
Original Poster
QuoteOriginally posted by JinDesu Quote
If you have other lenses that are working fine with the camera, then it's the lens problem.

I would say it counts as a manufacturing defect, and would qualify under warranty.
OK, I'll do that tomorrow, shall see what they have to say about it. But it's quiet strange because I never had this kind of problem and lens haven't been damaged anyhow

07-02-2012, 12:24 PM   #9
Pentaxian
JinDesu's Avatar

Join Date: Jun 2011
Location: New York City
Photos: Gallery
Posts: 5,626
QuoteOriginally posted by LenorAD Quote
OK, I'll do that tomorrow, shall see what they have to say about it. But it's quiet strange because I never had this kind of problem and lens haven't been damaged anyhow
Some other people have had the same issues with other lenses. It's generally where the mount is too tight for the lens to connect properly. Someone on this forum mentioned that their DA40mm LTD wasn't registering until they went and gave it a nice twist after putting it on.

It's sample variation, and unfortunately yours is just beyond the margins of tolerance.
07-02-2012, 12:40 PM   #10
New Member




Join Date: Jul 2012
Posts: 6
Original Poster
QuoteOriginally posted by JinDesu Quote
Some other people have had the same issues with other lenses. It's generally where the mount is too tight for the lens to connect properly. Someone on this forum mentioned that their DA40mm LTD wasn't registering until they went and gave it a nice twist after putting it on.

It's sample variation, and unfortunately yours is just beyond the margins of tolerance.
Well as I said I tried it already and harden twist didn't help.
I'll try to meet some people with other pentax cameras, shall see what happens and then i'll go to that shop
07-03-2012, 06:41 AM   #11
Site Supporter
Site Supporter
Pauld's Avatar

Join Date: Nov 2009
Location: Calgary, Alberta
Photos: Gallery | Albums
Posts: 507
I use 5 different Sigma lenses and recently 2 of mine have decided to not work on my K20. They worked perfectly fine up until a couple weeks ago when the decided to not register in the camera. I have tried both of them on my K10 and they work just fine so I know it is not the lenses that have issues. I've reset my camera to factory defaults, treid the suggested "twist" method and still nothing works. The lenses work perfectly fine otherwise and I have no issue using them in manual mode but it doesbug me knowing that they aren't working properly.
07-03-2012, 01:47 PM   #12
New Member




Join Date: Jul 2012
Posts: 6
Original Poster
I solved the problem by myself, lol. I started to twist the lens with out pressing lens release button and some contact went into it's place and AF now works, yay

Last edited by LenorAD; 07-03-2012 at 01:48 PM. Reason: missed word
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!
af, camera, display, lens, mf, pentax help, sigma
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
odd front focus problem with kit lens and Tamron 18 - 250mm lens jlaubza Pentax DSLR Discussion 12 10-30-2011 09:42 AM
Simga 120-400mm Non-OS baker5 Pentax SLR Lens Discussion 2 10-10-2011 04:00 PM
Is this a front focusing camera problem or lens problem? Lens tests Metalwizards Pentax K-r 15 03-06-2011 01:24 AM
Need help from Tamron/Simga Users COULDBE2 Pentax SLR Lens Discussion 2 09-18-2010 05:49 AM



All times are GMT -7. The time now is 07:50 PM. | 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