Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-10-2014, 01:32 PM   #1
Forum Member




Join Date: Jul 2013
Photos: Gallery | Albums
Posts: 70
K28 3.5 aperture ring

I just picked up a copy of this lens for $50 because the aperture blades are slow, but that should be fine. My question is that at 3.5 (wide open) the aperture ring doesn't really click into place, it just kind of stops. Is this normal?

Thanks

03-10-2014, 01:46 PM   #2
Veteran Member
ironlionzion's Avatar

Join Date: Dec 2010
Location: Dallas, TX
Posts: 409
Mine doesn't click in place either, at least not as firmly as the other stops. The ring still wants to sit at either 3.5 or 5.6, no in between. Probably normal.
03-10-2014, 02:01 PM   #3
Forum Member




Join Date: Jul 2013
Photos: Gallery | Albums
Posts: 70
Original Poster
Mine clicks between 3.5 and 5.6 (4?), but not at the 3.5.
03-10-2014, 05:20 PM   #4
Loyal Site Supporter
baro-nite's Avatar

Join Date: Aug 2011
Location: North Carolina, USA
Photos: Gallery | Albums
Posts: 4,365
Click, click, click.

03-10-2014, 06:01 PM   #5
Loyal Site Supporter
monochrome's Avatar

Join Date: Mar 2008
Location: Kirkwood (St. Louis) MO
Photos: Gallery | Albums
Posts: 20,447
QuoteOriginally posted by baro-nite Quote
Click, click, click.
Me too.
03-10-2014, 06:35 PM - 1 Like   #6
Pentaxian
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,864
If you have a JIS screwdriver, you can take off the mount, clean it up and regrease the aperture ring. The clicks are simple. The aperture ring has teeth inside, like the upper right here:



There's a bearing trapped between the ring and lens body, probably just below the orange diamond like here:



The bearing has a spring pushing it out against the teeth. Usually that's a flat piece of spring steel, riveted on one end to the inner lens body. The bearing can pop out unexpectedly when you slide the aperture ring off, so be ready, maybe do that in a plastic bag to capture the bearing. The original grease might have dirt packed into it. An old toothbrush and some mineral spirits can get all that grease off. The ring will work OK with no grease but just a dab will make it move smoother.
03-11-2014, 05:36 AM   #7
Forum Member




Join Date: Jul 2013
Photos: Gallery | Albums
Posts: 70
Original Poster
what kind of grease would work best?
03-11-2014, 05:46 AM   #8
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 4,263
I've been using a product HELIMAX-XP™ Camera Lens Telescope Optical Instrument Focusing Helicoid Grease w/ PTFE to relube my lenses. It is a high quality lubricant and I'm very satisfied with the results. A couple of other member have used it too and are pleased with the results.

You can find it on ebay and Amazon or direct from the manufacturer. They sell and ship internationally. Reasonably priced and a little goes a long way. A must if you will be buying more legacy lenses.

MicroLubrol? HELIMAX-XP? Camera Lens Telescope Optical Instrument Focusing Helicoid Grease w/ PTFE 1oz 28g

03-12-2014, 07:39 AM   #9
Forum Member




Join Date: Jul 2013
Photos: Gallery | Albums
Posts: 70
Original Poster
It now clicks. I guess just working it loosened up whatever grit was in there. I will still probably clean it though. Thanks for the tips.
03-18-2014, 11:12 AM   #10
Forum Member




Join Date: Jul 2013
Photos: Gallery | Albums
Posts: 70
Original Poster
Quick question, the screws on the back of this lens are really tight. What is the best way to loosen them? Normally I would spray some WD-40, but that is probably not a good idea for a lens.
03-18-2014, 12:20 PM   #11
Loyal Site Supporter
monochrome's Avatar

Join Date: Mar 2008
Location: Kirkwood (St. Louis) MO
Photos: Gallery | Albums
Posts: 20,447
QuoteOriginally posted by millsware Quote
Quick question, the screws on the back of this lens are really tight. What is the best way to loosen them? Normally I would spray some WD-40, but that is probably not a good idea for a lens.
Again (RE: DaveInPa) - I think they're probably JIS cross-type and not US/EU Phillips. That can make a difference applying torque (and can strip them if you use Phillips).

I don't see where you are. Have you considered sending it to Eric for a CLA? He adjusted the colimation on a K28/3.5 for me a few years ago
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, k-mount, k28 3.5 aperture, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Close-Up filters, Pentax K28/3.5,M 50/1.7, Kenlock Lens and ME (repair) Albino_BlacMan Sold Items 7 04-13-2013 11:34 AM
For Sale - Sold: K28 f/3.5 robbiec Sold Items 2 10-31-2011 01:56 AM
k28/3.5 , very impressive nirvanaguy19 Pentax SLR Lens Discussion 2 02-20-2008 11:22 PM
K28/3.5 schmikey Pentax SLR Lens Discussion 4 07-11-2007 05:34 PM



All times are GMT -7. The time now is 06:19 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