Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
09-25-2014, 11:00 AM   #1
New Member

Join Date: Feb 2009
Location: Poland
Posts: 4
SMC Pentax-F* 300mm F4.5 issues with auto aperture


I've just recently bought the lens from ebay. It is working great, but when the aperture ring is set on Auto, the camera (K10D) does not detect it.

What is working:
  • detect what lens is attached (it displays 300mm correctly in photo exif and focal length selector does not appear),
  • autofocus without issues,
  • shows aperture F4.5 when in Program mode.

What is not working:
  • in program mode, I can only shoot @ F4.5,

I've tried other lenses with the body (FA and DA) and they work flawlessly. I have also attached the F 300 to my SuperProgram and it was not detected by the program mode.

Did anyone ever had similar problem? Is it possible that some wires got loose in the lens and it doesn't send it's aperture to the body at all (while sending other lens information)? The seller said he can knock 100$ off the price or I can return it with full refund. I would like to keep it though as I think it is otherwise a great lens and the optics are in excellent condition, but if the repair will cost a lot more than 100$ (and in authorized Pentax service I guess it would), it is becoming less and less of an interesting deal.

Thanks for any help or tips.

09-25-2014, 11:19 AM   #2
Veteran Member
manntax's Avatar

Join Date: Jan 2012
Photos: Albums
Posts: 1,972
I suggest you clean the contacts on both lens and the camera mount with q-tip and some alcohol. I had very same issue with on of my F lenses - after cleaning it works flawlessly.
09-25-2014, 12:01 PM   #3
Site Supporter
Site Supporter

Join Date: Sep 2011
Location: Richland, Washington, USA
Posts: 925
I had a similar problem with an A85mm. Tried cleaning, didn't help. Finally sent the lens to Eric and came back perfect, never another problem, and didn't cost much to fix.

  • 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!
300mm f4.5 issues, aperture, auto aperture, body, f4.5, issues with auto, k10d, lens, mode, pentax help, pentax-f* 300mm f4.5, program, smc pentax-f* 300mm, smc pentax-f* 300mm f4.5
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
SMC Pentax-DA 55-300mm F4-5.8 ED vs SMC Pentax-DA* 300mm F4 ED [IF] SDM Budster48 Pentax SLR Lens Discussion 12 06-30-2013 11:00 AM
For Sale - Sold: SMC Pentax F* 300mm F4.5 ED (IF) lens, Serial # 1168341 fliegenfischer Sold Items 10 03-30-2013 07:15 AM
For Sale - Sold: Pentax SMC f*300mm f4.5 ivoire Sold Items 4 01-12-2013 06:13 AM
Aperture issue with SMC Pentax-FA 80-320mm F4.5-5.6 BNBPhoto Troubleshooting and Beginner Help 8 04-25-2012 01:45 AM

All times are GMT -7. The time now is 02:55 AM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]