Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-02-2013, 04:51 PM   #31
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,619
Original Poster
QuoteOriginally posted by rawr Quote
A useful set of tests and good results.


I suspect single centre point AF is not the best option for AF-C tracking.

In the Canon 1Dx AF settings User Guide, which is 1Dx focussed but a good guide to sports AF-C settings generally, they say:


One of the K-3's 'Expanded Area AF' or 'Zone Select' options may work better. They seem very similar to the 1Dx's 'AF Point Expansion' mode options.

Pentax need to put out a book on the new AF features. They have a lot of nuances, I suspect.
Yes. I definitely should have played with more of the AF zone features. I was shooting at F/2 or F/2.8 though and only the center 3 sensors are F/2.8 sensors. Most people however will be shooting at F/5.6 and could use the zone AF system. I was trying to challenge they system by using wider aperture (narrower DoF).

11-02-2013, 05:32 PM   #32
Veteran Member




Join Date: Sep 2007
Location: Cracow
Posts: 457
QuoteOriginally posted by Winder Quote
I was shooting at F/2 or F/2.8 though and only the center 3 sensors are F/2.8 sensors. Most people however will be shooting at F/5.6 and could use the zone AF system
Only center points have f/2.8 baseline, but it does not mean, that the rest of them can't be used with that aperture. It just means they have narrower baseline and slightly less precision. BTW, judging from some marketing materials, only the horizontal pair of sensors have a wider f/2.8 baseline, vertical pair uses narrower f/5.6 baseline only, so basically those "points" work on f/5.6 precision and use an additional f/2.8 pair of sensors as a support when the system needs more precision with faster lens. I even doubt if they are used in the AF-C mode where the AF system is tuned for speed rather than accuracy.
11-02-2013, 08:49 PM   #33
Veteran Member
richard balonglong's Avatar

Join Date: Aug 2007
Location: Baguio City, Philippines
Photos: Gallery
Posts: 350
Wow!
The AF-C really improves! I like!
Looking at the exposures of your photo, what was your Mode and what was your EV? By the looks of it, the photos (second batch) over exposes then was toned down through post-process... In short, how do you find the K-3's exposure metering in high contrast situation? =)

Last edited by richard balonglong; 11-02-2013 at 08:59 PM.
11-02-2013, 09:55 PM   #34
Forum Member
alcstudios's Avatar

Join Date: Sep 2011
Location: Texas
Photos: Albums
Posts: 85
Thanks for posting these shots, my K3 will be here Wednesday, from the look of your photos the AFC looks much improved over my half worn out K7

11-02-2013, 10:53 PM   #35
Forum Member
bgdisc's Avatar

Join Date: Dec 2010
Location: United States
Photos: Gallery
Posts: 90
It looks like the K-3 should be able to handle American Football (College, Division 1). I miss a lot of shots with my K-5 because the AF just can't keep up. Thanks for testing and sharing your results.
11-04-2013, 07:54 AM   #36
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,619
Original Poster
QuoteOriginally posted by bgdisc Quote
It looks like the K-3 should be able to handle American Football (College, Division 1). I miss a lot of shots with my K-5 because the AF just can't keep up. Thanks for testing and sharing your results.
I think the camera is more than capable of handling football. I was using the center AF point and and playing with the settings. The area AF would be great for large field sports. The only limitation now is lens speed.
11-04-2013, 08:39 AM   #37
Senior Member




Join Date: Oct 2008
Posts: 213
I would like to see how AF-C performs doing panning pictures, who can try ?
11-04-2013, 08:59 AM - 1 Like   #38
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,619
Original Poster
QuoteOriginally posted by Vaikis_ Quote
I would like to see how AF-C performs doing panning pictures, who can try ?
How is this?

Attached Images
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
11-04-2013, 09:13 AM   #39
Veteran Member




Join Date: Sep 2007
Location: Cracow
Posts: 457
Your object was at the same distance so it could be easy done with an old AF-C or even AF-S.
11-04-2013, 09:36 AM   #40
Veteran Member
Andi Lo's Avatar

Join Date: Jul 2008
Location: Halifax, Nova Scotia
Posts: 2,925
QuoteOriginally posted by jaad75 Quote
Your object was at the same distance so it could be easy done with an old AF-C or even AF-S.
Even minimal distance changes will make shots unsharp if shot with long FL / wide aperture (which he is doing in theses shots)

Great results on the K-3, looks very solid
11-04-2013, 10:14 AM   #41
Forum Member
wpompen's Avatar

Join Date: Mar 2013
Posts: 64
I can't wait to test the K-3 AF-C on a pack of sighthounds, already know my K5 is not keeping up at all! ;-)

Last edited by wpompen; 11-04-2013 at 10:14 AM. Reason: typo
11-04-2013, 10:47 AM   #42
Veteran Member




Join Date: Sep 2007
Location: Cracow
Posts: 457
QuoteOriginally posted by Andi Lo Quote
Even minimal distance changes will make shots unsharp if shot with long FL / wide aperture (which he is doing in theses shots)
Really? :P I could track birds in flight with rather poor AF-C of my K-5IIs with the DA*200 wide open. If the object moves across the frame at a constant distance it's not a challange for any AF system.
11-04-2013, 10:53 AM   #43
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,619
Original Poster
QuoteOriginally posted by jaad75 Quote
Your object was at the same distance so it could be easy done with an old AF-C or even AF-S.
No, he was not the same distance, and at F/2.8 the DoF of the 85mm is pretty narrow. I was standing in a turn where the rider was approaching at 120 degrees and turned and headed away at 90 degrees to my right.
11-04-2013, 10:59 AM   #44
Pentaxian
JinDesu's Avatar

Join Date: Jun 2011
Location: New York City
Photos: Gallery
Posts: 5,624
The distance changed from the first shot.
11-04-2013, 11:05 AM   #45
Veteran Member




Join Date: Sep 2007
Location: Cracow
Posts: 457
QuoteOriginally posted by Winder Quote
No, he was not the same distance
The distance change looks pretty small anyway.
QuoteOriginally posted by Winder Quote
and at F/2.8 the DoF of the 85mm is pretty narrow
It's not that narrow, but narrow enough to show some errors.
I'm still waiting for samples of K-3 tracking subjects in erratic movement.
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!
af, af-c, center, dslr, k-3, k3, pentax k-3, shot, test
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Sigma Bigma 50-500mm F4-6.3 EX APO DG AF MINT C$750 Tony Evans Sold Items 2 03-12-2013 03:15 PM
First AF test K-5 vs K-5IIs ogl Pentax K-5 8 11-01-2012 05:46 PM
K-5 AF.S / AF.C / MF switch defective? DSK5 Pentax K-5 7 04-06-2012 05:05 PM
Pentax K-x: focus confirmation in AF-S, AF-C, not AF-A manteiv Pentax DSLR Discussion 24 12-10-2010 07:25 PM
Kr AF-C test dijkx Pentax K-r 5 11-16-2010 08:25 AM



All times are GMT -7. The time now is 05:05 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