Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-05-2011, 06:46 PM   #1
Senior Member




Join Date: Jan 2009
Posts: 173
Slow Diaphragm Blades on K 28mm f3.5

Hey guys, the diaphragm blades on my K28 f3.5 are a bit slow. I took the mount off to see what's the matter, and to me it seems like the ring with the aperture lever is rubbing again the mount at some point. When I take off the mount everything seems to be pretty good. I've read somewhere recently that K series lenses tend to develop this problem, so I was wondering if any of you've guys found a way to solve this issue.

I tried applying some lube, which didn't seem to help. Also tightened all the screws to make sure they don't stick out. The lens now works much better than when I bought it, like I couldn't even use it at f8 because the blades were too slow. But I think I can now crank it up all the way to f16. However, f22 seems to be a bit too slow. I don't want to start sanding things off just yet to make sure I don't mess it up. Any tips? Thanks.

04-05-2011, 06:57 PM   #2
Senior Member




Join Date: Jan 2009
Posts: 173
Original Poster
I have just taken a look inside my 55mm f.18 and noticed there is a little plastic piece separating the mount from the ring, I wonder if Asahi became aware of the problem and this was their fix, or if that plastic piece is for something else entirely.
04-06-2011, 03:57 AM   #3
Senior Member
wavecurrent's Avatar

Join Date: Jul 2007
Location: Kiruna, Sweden
Posts: 147
I have had a similar problem with a K-lens, I fixed the problem by cleaning the ring all together. Once the ring an all surrounding surfaces were clean, the aperture worked perfectly.

Mike
04-06-2011, 04:24 PM   #4
Senior Member




Join Date: Jan 2009
Posts: 173
Original Poster
Ok, I guess I'll try it. I think the lens is now closing to f22 on time but when I move the lever I still sort of feel the resistance of something rubbing. My other K's don't show this problem. Oh well, thanks for the advice.

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!
bit, blades, diaphragm, f3.5, guys, k-mount, mount, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Vivitar 28mm F2 aperture blades zoeybird Pentax SLR Lens Discussion 38 01-08-2017 04:40 PM
DA 40 Diaphragm Blade Problem? Colorado CJ Pentax SLR Lens Discussion 31 12-26-2010 01:40 AM
Slow Aperture blades on my M-28/2.8, how to proceed? fazer Pentax SLR Lens Discussion 4 06-09-2010 04:07 AM
Slow AF? Slow TTL? Check 'em batteries!!! jboyde Pentax DSLR Discussion 11 04-30-2009 06:41 PM
How to fix sticky/slow blades? TimB Pentax SLR Lens Discussion 35 09-22-2008 09:01 AM



All times are GMT -7. The time now is 10:03 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