Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-21-2011, 05:17 PM   #1
Site Supporter
Site Supporter
Spodeworld's Avatar

Join Date: Aug 2011
Location: New Joisey
Photos: Gallery | Albums
Posts: 1,370
Just received a SMC Pentax-A - Aperture Ring Question

Hi. I just received a SMC Pentax-A 28mm f2.8 lens, and it seems that the aperture ring does not turn even though the button is pressed (I am able to turn it on the 50mm A that way). It seems though that the lens works fine on the camera. When I change the camera dial, the aperture readout in the display changes as it should. And, the exposure changes as it should. However, I am wondering if anyone has any ideas what I can do such that the aperture ring itself can be turned manually. Or, since it is on A and works fine in that mode, is it best just to leave it alone?

Thanks.


Last edited by Spodeworld; 11-21-2011 at 05:24 PM.
11-21-2011, 05:31 PM   #2
Veteran Member




Join Date: Jan 2010
Location: Vancouver, BC
Posts: 1,421
I have read that the aperture ring on A series lenses can be finicky. If your lens works as it should for the entire aperture range in the AE mode, I would leave it alone. Only reason for turning the aperture ring would be if you are reversing the lens and want to be able to stop down, use other MF lenses instead.
11-21-2011, 05:34 PM   #3
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 51,558
If the automation works I wouldn't worry about it, it might be a more involved repair.

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:
11-21-2011, 05:39 PM   #4
Site Supporter
Site Supporter
Spodeworld's Avatar

Join Date: Aug 2011
Location: New Joisey
Photos: Gallery | Albums
Posts: 1,370
Original Poster
Thanks..the automation seems to be working fine...maybe I'll leave well enough alone. I think I know what would happen if I ventured inside the lens anyway, and it wouldn't be pretty.

11-21-2011, 07:39 PM   #5
Senior Member




Join Date: Jan 2009
Posts: 173
The aperture ring on A lenses is rather wicked, I took my A 28mm f2 apart to re-lube the focusing coil, took me about 2 weeks to put it back together.
11-22-2011, 08:00 AM   #6
Site Supporter
Site Supporter
Spodeworld's Avatar

Join Date: Aug 2011
Location: New Joisey
Photos: Gallery | Albums
Posts: 1,370
Original Poster
Just the kind of horror story I was worried about. Of course, my story might end "I still haven't been able to put it back together." I should leave well enough alone. It works perfectly fine in A mode.

QuoteOriginally posted by VaSA Quote
The aperture ring on A lenses is rather wicked, I took my A 28mm f2 apart to re-lube the focusing coil, took me about 2 weeks to put it back together.
11-22-2011, 08:49 AM   #7
Site Supporter
Site Supporter
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,807
The A lenses tend to have a spring come unglued that then lodges in the mechanism and prevents the ring from turning.
See Pentax 50mm lens fix
I have done this repair before on a 50mm and the important thing is to disassemble in a Ziploc bag because the tiny detent bearing may fly out.
However if yours is already on the A position and you don't plan to sell it you may just want to leave well enough alone.

11-22-2011, 08:49 AM   #8
Veteran Member




Join Date: Oct 2010
Location: Taiwan
Photos: Gallery | Albums
Posts: 1,075
One reason that the aperture ring is finicky on A level lenses is that most of them have not been twisted in 15-20 years. But there is no reason to move it imo.
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!
aperture, camera, changes, lens, pentax help, pentax-a, photography, smc
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax-A 50mm f1.7 Aperture ring repair Just1MoreDave Maintenance and Repair Articles 77 11-06-2023 05:58 PM
Stubborn aperture ring on SMC-A 50 f/1.7 Sluggo Pentax SLR Lens Discussion 10 01-07-2015 11:07 PM
FA Limiteds on bellows. Aperture ring question. mccarvindh Pentax SLR Lens Discussion 5 02-24-2011 09:35 AM
Use of Aperture-Ring 43mm/1.9 -> no aperture data Deimo Pentax SLR Lens Discussion 7 06-24-2009 03:25 PM
Aperture ring on lenses for Pentax? Duh_Vinci Pentax SLR Lens Discussion 5 12-06-2006 09:24 PM



All times are GMT -7. The time now is 12:27 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