Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-16-2015, 07:03 AM   #1
Pentaxian




Join Date: Mar 2010
Location: Manila, Philippines
Posts: 1,014
AF points for f2.8

Hi, does the KS-2 have this? Same as the K-3 and the 5ii/s? I know rhe KS-2 has the -3EV AF whicg is very good for lowlight but as for having the AF for with F2.8's I am not sure.

Thank you

06-16-2015, 01:15 PM   #2
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 40,979
It's the exact same AF system as the K-5 II. The K-3 has three F2.8 points, and the K-5 II either has 1 or none. Can't remember off the top of my head, I also don't think it makes much of a practical difference.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

06-27-2015, 10:00 AM   #3
Loyal Site Supporter
bwDraco's Avatar

Join Date: Jul 2010
Location: New York
Photos: Albums
Posts: 1,007
On the K-5 II and K-S2, the center point is f/2.8 high-precision. The f/2.8 sensor is vertical line-sensitive; focusing is limited to standard precision if the subject has only horizontal contrast.

On the K-3 and K-3 II, the middle three points in the center column of the AF array are f/2.8 high precision. The f/2.8 sensors are vertical line-sensitive as well.

In all cases, these points revert to standard-precision cross-type focusing with slower lenses.

—DragonLord

Last edited by bwDraco; 06-27-2015 at 10:07 AM.
06-27-2015, 02:47 PM   #4
Pentaxian




Join Date: Mar 2010
Location: Manila, Philippines
Posts: 1,014
Original Poster
DragonLord,

Thank you for your clarification. What is the advantage of having more points? Thank.

06-27-2015, 04:12 PM - 1 Like   #5
Loyal Site Supporter
bwDraco's Avatar

Join Date: Jul 2010
Location: New York
Photos: Albums
Posts: 1,007
More points allow for greater flexibility and more precision when selecting where to focus. It also allows for more accurate focus tracking, where the camera can collect more distance information allowing it to better maintain focus on a fast-moving subject.

—DragonLord
06-29-2015, 05:26 AM - 1 Like   #6
Veteran Member




Join Date: Jul 2007
Location: Sweden
Posts: 841
If you have few focus points you may need to re-arrange the composition to get one of the focus points at the subject and then-recompose to get the final image. With more focus points you have a higher chance that you find a focus point where you have the subject, or at least one will be close so you'll have to move the camera less - this also gives sharper focus since if you move the camera after you have set the focus - you actually change the camera-to-subject distance - this may be a problem with lenses and/or aperture settings that gives a short depth-of-field.
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, k-s1, k-s2, ks-2
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
What means 'f=2.8 AF points'? Prakticant Pentax K-3 3 02-23-2015 01:54 PM
Sigma 24-70mm F2.8 EX DG Macro or Tamron 28-75mm F2.8 AF XR Di LD Macro for KR ? ajaya Pentax SLR Lens Discussion 9 12-05-2012 11:30 PM
For Sale - Sold: Pentax K30mm/F2.8, K105mm/F2.8 and Tokina 400mm/F5.6 ATX AF lens for Pentax coolgobi Sold Items 7 12-27-2011 02:54 PM
For Sale - Sold: Tokina AT-X 28-80mm F2.8 SD AF PRO for Pentax AF (CONUS) luke0622 Sold Items 5 04-16-2010 05:06 AM



All times are GMT -7. The time now is 05:06 AM. | See also: NikonForums.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