Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
06-25-2011, 06:51 PM - 1 Like   #1
New Member

Join Date: May 2011
Posts: 15
my focus rig

Testing out the focus fine adjustment on my K5. Rig with high-precision optical table components seems to work pretty well. I notice some dependence on the lighting type and intensity and repeatability after far-focusing. Tried to get the best compromise and not let OCD get the best of me.

Any tips/techniques to share?

Here are my current settings:

FA31: 0
FA43: -3
DA15: +2
DA18-135: +2


06-25-2011, 07:01 PM   #2
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
Nice set-up thanks for sharing.
06-25-2011, 09:33 PM   #3
Veteran Member
yeatzee's Avatar

Join Date: Feb 2009
Location: Temecula
Photos: Gallery | Albums
Posts: 3,675
Linear stage FTW?
06-25-2011, 10:03 PM   #4
Veteran Member

Join Date: Mar 2009
Location: Chicago suburbs
Photos: Albums
Posts: 848
Very nice set up.

06-25-2011, 10:03 PM   #5
New Member

Join Date: May 2011
Posts: 15
Original Poster
Yep, pair of rescued linear stages. I think I'm going to rotate the one holding the chart so that I can autofocus on the center and evaluate focus on the same center, as opposed to autofocus center and evaluate edge. I'll do the stage move between button press and exposure (2sec.).

06-25-2011, 11:17 PM   #6
Veteran Member
wlachan's Avatar

Join Date: Sep 2006
Location: Canada
Photos: Albums
Posts: 2,626
AF test at such close distance is a waste of time.
06-26-2011, 02:27 AM   #7
Loyal Site Supporter
imtheguy's Avatar

Join Date: Mar 2009
Location: Virginia Beach
Photos: Gallery | Albums
Posts: 2,950
QuoteOriginally posted by wlachan Quote
AF test at such close distance is a waste of time.
When I noticed that I realized its likely just set that close to show the setup. But I have read the same stuff about minimum distance to do focus corrections.

Of course my setup is the opposite side of the universe from RGK's very organized and precise looking test bed. I usually just find a spot on some otherwise feature-less concrete and shoot spot at a 45 angle while kneeling to adjust an inch up or back. Justification is I try to test and alight everything in the same light and stability I use it for real. I could be right...or just lazy.
06-26-2011, 12:04 PM   #8
New Member

Join Date: May 2011
Posts: 15
Original Poster
Yeah, I pushed things together to get a pic, but I was using a pretty close focus distance, say under 24". I could get about 6' on my table, or much longer with some creativity. Will use these tests to supplement real-world use.

Background here is that I was noticing some minor focus issues and became aware of the fine focus adjust feature on my new K5. Too cool to resist. Tested out the folded paper Bourque method, but thought I could take it up a notch pretty easily. Will keep experimenting and appreciate any suggestions on technique/setup/patterns.



  • 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, k-mount, pentax lens, rig, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
Binocular Lens Macro Rig Paleo Pete Pentax SLR Lens Discussion 13 03-07-2013 06:16 AM
What's your video rig? inferno10 Video and Pentax HDSLRs 6 05-05-2011 08:19 AM
Macro My new watercooled rig FrancisK7 Post Your Photos! 7 01-05-2011 09:11 PM
Night Night time drill rig penmaker Post Your Photos! 6 12-06-2009 06:38 AM
Mobile flash rig PentaxPZ Flashes, Lighting, and Studio 8 08-15-2009 10:08 AM

All times are GMT -7. The time now is 07:53 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]