Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-16-2014, 02:54 PM   #1
Senior Member
dmfw's Avatar

Join Date: Dec 2009
Location: Dallas, Tx
Photos: Albums
Posts: 159
Older K Mount lens: Will they Autofocus?

I have a K-X and I know that older Pentax lenses will mount to the body. However, will the K-X's auto-focus system work with older lenses? If there is an age limit, what is the general date where the K-X's will no longer auto-focus the lens?

Thank You.

07-16-2014, 02:59 PM   #2
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
If a Pentax-brand lens does not say F, FA, or DA on the front, it is a manual focus lens. Similarly, most 3rd-party AF lenses are prominently labeled as such. Proof positive is the presence/lack of the AF drive fitting an/or the AF contacts on the mount.

When using manual focus, you still have the option of focus confirmation. The AF system will signal when it has determined that focus has been attained. Focus confirmation is limited to the center spot focus sensor.


Steve
07-16-2014, 03:01 PM   #3
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 51,558
QuoteOriginally posted by dmfw Quote
I have a K-X and I know that older Pentax lenses will mount to the body. However, will the K-X's auto-focus system work with older lenses? If there is an age limit, what is the general date where the K-X's will no longer auto-focus the lens?

Thank You.
All AF Pentax lenses (with the exception of the M-era AF 35-70mm F2.8) are fully supported by the K-x, so you don't have to worry about compatibility.

AF lenses include the F, FA, FA J, D FA, DA L and DA series.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:
07-16-2014, 03:05 PM   #4
PJ1
Loyal Site Supporter
Loyal Site Supporter
PJ1's Avatar

Join Date: Jul 2012
Location: Toowoomba, Australia
Photos: Gallery | Albums
Posts: 5,460
No. Only the F, FA and DA lenses have the capacity to autofocus. Older lenses (M, K and the M42 glass) have to be manually focused (as we all had to in the old days). It is not much of an issue in many situations and gets you relatively inexpensive access to some great lenses. There is a good article here by Adam on "How to use/meter Manual & M42 Lenses on all Pentax DSLRs (K-5, K-r, K-x, K-7...)".

07-16-2014, 03:42 PM   #5
Forum Member




Join Date: Apr 2011
Location: Southern UK
Posts: 93
Unless you have a Pentax auto-focus adaptor, in which case the manuals will autofocus (well strictly the adaptor focusses it).

AFA Review
07-16-2014, 05:28 PM   #6
Veteran Member




Join Date: Feb 2012
Location: Fredericton, New Brunswick
Photos: Gallery
Posts: 632
QuoteOriginally posted by SteveUK Quote
Unless you have a Pentax auto-focus adaptor, in which case the manuals will autofocus (well strictly the adaptor focusses it).

AFA Review
Now if only Pentax would start selling that sort of stuff again...(DA AFA 1.2x would be nice, haha)
07-16-2014, 06:10 PM   #7
Veteran Member




Join Date: Jan 2013
Location: Nanaimo, British Columbia
Photos: Albums
Posts: 328
QuoteOriginally posted by stevebrot Quote
When using manual focus, you still have the option of focus confirmation. The AF system will signal when it has determined that focus has been attained. Focus confirmation is limited to the center spot focus sensor.


Steve
Steve is correct of course, but I see "Catch in Focus" as a tool that allows me to cheat a bit. You set it, press the release and focus until the picture is taken. Just thought I'd add that as it wasn't mentioned earlier.

07-16-2014, 09:43 PM   #8
Site Supporter
Site Supporter
bkpix's Avatar

Join Date: Feb 2010
Location: Creswell, Oregon
Photos: Albums
Posts: 568
The perfect new optical offering from Pentax would be a 0.65x autofocus adapter, so you could use your M 28/2.8 as an autofocusing 28mm lens on a K-5 or K-3.
07-17-2014, 12:57 AM   #9
Pentaxian
bassek's Avatar

Join Date: Feb 2011
Photos: Gallery
Posts: 706
QuoteOriginally posted by bkpix Quote
The perfect new optical offering from Pentax would be a 0.65x autofocus adapter, so you could use your M 28/2.8 as an autofocusing 28mm lens on a K-5 or K-3.
A full frame adapter! Thats ingenious!

Seb
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-focus, k-mount, lens, lenses, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Will not mount-> K mount Rokinon 85mm f/1.4 Korg Troubleshooting and Beginner Help 8 07-14-2014 02:28 PM
16-50mm lens won't autofocus on k30, but will with other bodies Immunogirl Pentax SLR Lens Discussion 2 04-20-2014 10:20 PM
Ricoh Imaging Enhances K-Mount Lens Lineup with Debut of Rear Converter Autofocus Fun Adam Homepage & Official Pentax News 5 02-06-2014 09:22 PM
Will a new K mount lens for a DSLR work on my ME Super? iamtheju Film SLRs and Compact Film Cameras 5 12-27-2012 06:53 AM
If they hold it ... they will shoot daacon Post Your Photos! 16 07-12-2009 09:05 PM



All times are GMT -7. The time now is 11:03 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