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06-16-2015, 07:03 AM   #1

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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
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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.

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06-27-2015, 10:00 AM   #3
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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.


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

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

06-27-2015, 04:12 PM - 1 Like   #5
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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.

06-29-2015, 05:26 AM - 1 Like   #6
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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.

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