Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
10-17-2011, 01:55 PM   #1
Veteran Member

Join Date: Nov 2009
Location: Iowa
Photos: Albums
Posts: 2,275
Zoom lens won't focus to infinity - ideas?

Hey there lens repair folks...

I recently scored a 28-200mm Sakar zoom which seems to be a pretty nice lens aside from the fact that it won't focus to infinity when zoomed out to the long end. (from about 70-200mm.)

It seems I've heard on some lenses you can roll back the rubber grip on the focusing ring, loosen three screws around the barrel, and move the focusing ring a bit more toward the infinity end & re-tighten the screws to adjust the infinity "stop" point.

Any of you lens repair types know if this is true?

Bobbo :-)

10-17-2011, 02:47 PM   #2
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,328
Many of the Takumar lenses that I have permit adjustment of the infinity focus by loosening three tiny screws and moving the infinity scale ring. Getting it right is trial and error and very tedious.

I've never seen a Sakar lens so not sure if the same is true there or not, but it is possible.
10-17-2011, 03:03 PM   #3
Veteran Member

Join Date: Nov 2009
Location: Iowa
Photos: Albums
Posts: 2,275
Original Poster
So what's the best way to loosen the rubber grip?
10-17-2011, 07:02 PM   #4
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 5,744
Something thin and long. I have a common screwdriver with a long blade that I slip under the top or bottom, push under the rest, then roll around the whole lens so it breaks the glue bond. Then I use the screwdriver to lift one edge and start sliding the grip off, again rolling around the lens.

But first, check the front element. Some Pentax zooms have the front group of lenses in a threaded carrier that screws into the front tube of the lens. On these, you can adjust infinity by screwing this carrier in or out. It's supposed to be locked in place, possibly with threadlock or a locking ring with spanner slots. If it becomes unlocked and is loose, over time it can shift and infinity focus is lost.

10-17-2011, 07:12 PM   #5
Veteran Member

Join Date: Nov 2009
Location: Iowa
Photos: Albums
Posts: 2,275
Original Poster
Thanks for the info, guys! Something to try, anyway.

Bobbo :-)
10-22-2011, 07:56 AM   #6
Junior Member

Join Date: Jun 2010
Photos: Gallery | Albums
Posts: 47
Same Issue with Pentax-f 70-210

Any thoughts on where the screws are located on this lens to correct the infinity issue? Thanks for any help you can provide.

  • 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!
focus, focus to infinity, infinity, k-mount, lens, lens won't focus, pentax lens, repair, screws, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
Nice lens (sample) but adapter does not focus to infinity on K-5 Chazz5 Troubleshooting and Beginner Help 11 02-07-2013 06:44 PM
Asahi Super-Takumar 1:1.8/55mm Lens won't focus to infinity bingostew Pentax SLR Lens Discussion 15 10-25-2012 08:19 AM
Having no infinity focus on manual lens? clockwork247 Troubleshooting and Beginner Help 17 12-23-2010 04:22 PM
M42 lens trap, focus infinity? kiwao Pentax SLR Lens Discussion 5 03-11-2010 02:56 AM
Infinity Focus DblArrow Pentax SLR Lens Discussion 2 01-24-2010 01:03 AM

All times are GMT -7. The time now is 08:10 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]