Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-25-2010, 03:36 PM   #1
Inactive Account




Join Date: Nov 2009
Location: saskatoon
Posts: 16
retro fitting and not able to focus HSM lenses

Hello Everyone,

I have a chance to buy a Nikor 180 for a good price. Eny know if the nikor lens can be retro fit to a K20? Just wondering... I am seroiusly wnting a midrange tele
The pentax 200 2.8 is currently at the top of my list-but current financial situation mkex the 200 a bit out of range. My other issue is that my K20 will not focus a Third party AF lens (ie Sigma...) I'm told I will need to send it to Pentax to correct the problem and wouldn't see again for about 6 weeks! Anyone have any recommendations on resolving this issue? It is still under warrany - but 6 weeks?!

John

04-25-2010, 03:55 PM   #2
Inactive Account




Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,485
QuoteOriginally posted by John Wiggs Quote
Hello Everyone,

I have a chance to buy a Nikor 180 for a good price. Eny know if the nikor lens can be retro fit to a K20? Just wondering... I am seroiusly wnting a midrange tele
The pentax 200 2.8 is currently at the top of my list-but current financial situation mkex the 200 a bit out of range. My other issue is that my K20 will not focus a Third party AF lens (ie Sigma...) I'm told I will need to send it to Pentax to correct the problem and wouldn't see again for about 6 weeks! Anyone have any recommendations on resolving this issue? It is still under warrany - but 6 weeks?!

John
SOME Nikkor Lenses will fit the pentax mount without modification. They (the one I have) doesn't twist all the way on but it's snug enough to stay there. Of course, full manual aperture and focus with these. I know a lot of people use one of the Nikon 85mm lenses as well.

As for your K20d. If it will autofocus OTHER lenses, then the problem isn't likely to be your camera. Check thoroughly before sending it in.

04-25-2010, 10:21 PM   #3
Inactive Account




Join Date: Nov 2009
Location: saskatoon
Posts: 16
Original Poster
nikkor lens and HSM focus

Thanks Jeff,

I was a little taken back that my New K20 wouldn't focus a sigma or tamron lens. I tried several different lenses and none of them would AF. My 35 limited focuses perfectly. How can that be? They use the same electronic contacts as the Pentax lenses do they not?

John
04-25-2010, 11:52 PM   #4
Inactive Account




Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,485
I guess I did not read your title clearly enough, and did not realize you were asking about HSM. I'm afraid I'm going to be of little help in that respect. The HSM (and SDM) use a different set of contacts to control the in lens focus motors (HSM is similar to SDM, Correct?). The 35mm Limited is a screw drive focus and is driven by the focus motor in the camera. One of the many complaints of SDM, is that when it quits working, there is no way to switch the lens to screw drive focus (if so equipped, the 17-70 and the 55 are not) and the lens becomes a manual focus lens at that point. It hasn't happened to me but has to others.

It's a REAL long shot but us there any chance there's an AF/MF switch on the HSM lenses that you've turned off? If you were using these lenses on a Pre-K10d or a K10d pre firmware 1.3, The SDM (HSM) is not enabled on those cameras so it may have been using screw drive. Just a couple extra thoughts..



04-26-2010, 12:28 AM   #5
Veteran Member
sterretje's Avatar

Join Date: Dec 2008
Location: Roodepoort, South Africa
Photos: Gallery | Albums
Posts: 3,534
Can you tell more about the problem with the AF. Does it not AF at all or is it out-of-focus? Did you try to adjust in your K20D (in the latter case)?

Anyway, what I have heard is that Pentax will not calibrate third party lenses against a Pentax body. I suggest that you contact Sigma. I have read one or two good things (here on the forum) about their service. It's advised to send both body and lens to them.

Good luck
04-26-2010, 10:50 AM   #6
Inactive Account




Join Date: Nov 2009
Location: saskatoon
Posts: 16
Original Poster
The AF with pentax lenses is great. I tried a couple of Sigma lenses in the camera shop and they had the AF/MAN switch on the lens barrels. Flipping the switches back and forth did nothing to initiate AF with my K20. If I were to purchase an HSM motored lens I would have to manual focus it.
04-26-2010, 11:15 AM   #7
Veteran Member
sterretje's Avatar

Join Date: Dec 2008
Location: Roodepoort, South Africa
Photos: Gallery | Albums
Posts: 3,534
As said, contact Sigma. Maybe that the rechipping that I read about solves that issue.
04-26-2010, 11:30 AM   #8
Inactive Account




Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,485
QuoteOriginally posted by John Wiggs Quote
The AF with pentax lenses is great. I tried a couple of Sigma lenses in the camera shop and they had the AF/MAN switch on the lens barrels. Flipping the switches back and forth did nothing to initiate AF with my K20. If I were to purchase an HSM motored lens I would have to manual focus it.
Do you have any DA* (star) lenses? If not can you try one at the camera shop? If THEY work, that would isolate the lens from the camera or at least tell you that the camera is working as it should. Any one would do. The K20d will not revert to screw drive if SDM (HSM) is not working (a sore spot with many on this and other forums). If not, it may in fact Be the camera. I would be surprised if a Sigma HSM lens had to be re chipped to work on the K20d. SDM predates HSM if I am not mistaken. Anything is possible though.

Good luck with it..



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!
camera, dslr, focus, issue, k20, lens, pentax, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sigma 70-200 HSM and front-back-focus alexulo Pentax SLR Lens Discussion 0 04-08-2010 05:34 AM
SDM and HSM focus speed - dependent on body? Big G Pentax SLR Lens Discussion 1 10-12-2009 02:19 PM
Sigma 70-200 HSM Slow Focus Issue joelovotti Pentax SLR Lens Discussion 2 09-14-2009 06:12 PM
Split screen focus for K2? can it be retro-fitted? albrechtnamatdurer Pentax Film SLR Discussion 7 01-23-2009 10:00 AM
Minolta MD lenses fitting on Pentax body? kuuan Pentax DSLR Discussion 1 02-10-2008 09:09 AM



All times are GMT -7. The time now is 01:30 AM. | See also: NikonForums.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