Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
11-29-2010, 11:09 PM   #16
New Member

Join Date: Nov 2010
Location: Los Angeles
Posts: 20
Original Poster
Thanks for the info!

Wow guys, thanks a lot for all of these responses! Its been very informative for a beginner over here.

It seems like the general practice is center point focus & re-compose, except in some specific instances that require some workarounds.

Its interesting that so much has been made of the lack of indicator points when the majority of people responding (to this thread at least) don't describe instances where the AF lights are anything more than "a convenience" as snostorm said.

I have to admit that the lack of AF indicators had made me a bit concerned and I was wondering whether the K-x was going to prove frustrating in practice it seems like as long as I use the center point as the default and manual select points as a fallback or - full auto as required - this is going to be a non-issue.

Really great info folks, thanks for it and I'm looking forward to being part of the community!

Last edited by BradH; 11-29-2010 at 11:18 PM.
12-02-2010, 04:26 PM   #17
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 9,178
QuoteOriginally posted by BradH Quote
It seems like the general practice is center point focus & re-compose, except in some specific instances that require some workarounds.
Yes, focus & re-compose seems to be the most common mode of operation, but note that it is a workaround for having an AF sensor exactly where you need it. Hence, I wouldn't call the other modes of operation "workarounds".

I always use multiple AF points but manually control which one is active for two reasons.

1. This avoids "focus & re-compose" focus errors (I did some calculations to work out the magnitude of the problem). Note that staying "within DOF" is not that same as "tack sharp". DOF just defines acceptably sharpness but if you pixel peep or are ultra-critical you want a point on the subject to be exactly focused on, not just "within DOF". There are Hasselblad MF cameras which automatically adjust the focus while the photographer recomposes by measuring the amount of rotation. Hasselblad wouldn't do this, if it weren't useful.

2. It helps to get more interesting action photos. Let's assume you want to take a picture of an ice hockey player when he is charging the goal. The player should be in focus but in the composition you want the player to be off-centre. To do this, select the appropriate off-centre AF point. Leave it there; no more work to do. Keep focusing (e.g., with AF-C or by repeatedly activating AF-S) panning along with the player as he moves towards the goal. In the decisive moment, say when the goal enters the frame, you press the shutter button. The result is an off-centre player in focus. No way you can do this with focus & recompose with the same precision of focus and timing.

  • 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!
af, camera, center, dslr, focus, k-x, photography, question
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
A Question about K-7 oxidized Troubleshooting and Beginner Help 9 12-17-2009 09:56 AM
K-m question adwb Pentax DSLR Discussion 3 10-30-2009 12:13 PM
K-x question mba1971 Pentax DSLR Discussion 8 10-28-2009 11:49 PM
KM question jdg Pentax DSLR Discussion 4 06-08-2009 01:07 PM
An Answer to a question and a question. granitic Pentax DSLR Discussion 5 02-23-2007 09:28 AM

All times are GMT -7. The time now is 02:33 PM. | 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]