Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-02-2009, 05:07 AM   #1
Pentaxian
danielchtong's Avatar

Join Date: Jul 2007
Location: Toronto
Posts: 848
Improving AF with some MF finetuning?

I have noticed recently one way of improving AF focus lock of my DA200mm is to manually shift the focus distance to infinity (BTW great shift mechanism) prior to shooting subject further away.
And if I am aiming at closer subject I manually shift the focus to min. focus distance.
By manually setting the focus distance, the lens can have only one way , instead of the other way, to lock focus of the subject.
The ideam came when I shoot my manual focus A300mm. I always set to around 120 ft mark as I usually aim at my subject around 80 ft away (for bif shots). In that way I always shift the focus ring counter-clockwise. That gives me more keepers in locking focus a lot faster.

Daniel



QuoteOriginally posted by Lowell Goudge Quote

a great example is my sigma 70-200F2.8 it has 1/4 turn (90 degrees) from minimum focus to infinity. to make the comparison truely equal, add a 2x TC. Now I have 400mm F5.6 with an extremely narrow DOF and only a very limited adjustment range to get it perfect. Compare this to my manual focus vivitar 400mm F5.6 and I have amost a full turn (330 degrees) of fotation of the focusing collar.


05-02-2009, 07:03 PM   #2
Veteran Member




Join Date: Jun 2008
Location: Borås, Sweden
Photos: Gallery
Posts: 3,165
Nothing wrong with that approach. In fact, I saw a prominent bird photographer recently suggest using that for when you're using a teleconverter as those tend to impact AF performance a bit.
05-03-2009, 01:04 AM   #3
Veteran Member




Join Date: Jan 2009
Location: Budapest
Posts: 821
QuoteOriginally posted by danielchtong Quote
I have noticed recently one way of improving AF focus lock of my DA200mm is to manually shift the focus distance to infinity (BTW great shift mechanism) prior to shooting subject further away.
And if I am aiming at closer subject I manually shift the focus to min. focus distance.
I do the same when I change the FL from one end to the other (e.g from 50 to 200mm) or aim a closer subject after a faw away one. This shortens the time of auto focusing - the sound of the screwdriver AF scares aways my targets if it has to go through the entire focus range.
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!
400mm, af, camera, degrees, distance, dslr, f5.6, focus, ft, infinity, photography, shift, subject
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
The Economy Is Improving graphicgr8s General Talk 22 05-21-2010 07:26 PM
Improving your photography skills-what, how, why ? lesmore49 Photographic Technique 7 05-14-2009 11:26 PM
improving bokeh Urmas R. Pentax SLR Lens Discussion 35 04-08-2009 06:31 AM
Improving old photos Cloudy Wizzard Digital Processing, Software, and Printing 0 01-06-2008 11:54 AM
Improving Autofocus speed on DS ngkmh Pentax DSLR Discussion 2 09-06-2007 01:07 AM



All times are GMT -7. The time now is 01:18 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