On 2015-07-29 19:14:47 +0000, PeterN said:

On 7/28/2015 10:58 PM, Bill W wrote:
On Tue, 28 Jul 2015 18:25:30 -0700, Savageduck
wrote:

BTW: This is an extreme example of why AF-C and multi-AF point 3D
tracking can work to save a capture. This was an 8 frame burst with a
fast right to left pass which was completed in 2.25 seconds. I was
doing my best to hold to center, but not everything goes to plan.

This shows where the AF point was when lock was made. Without the 51
point AF matrix I would have been SOL.
https://dl.dropboxusercontent.com/u/1295663/FileChute/screenshot_238.jpg

...and here is the cropped final result after LR processing.
https://db.tt/tEtHO81e

What is 3D tracking? My problem at this air show location with all
those focus points is that it will start focusing on the power lines,
trees, mountains, clouds, etc. Does it mean that it tries to track
objects that are at a consistent distance? My Pentax does not have
that option, so it might be moot anyway.

For my own bird shots I usually use one point focus. (left, right, or
center.) At times when needed, I switch to five points. I think that
fifty-one points can easily confuse the camera.

The photographer is more likely to be confused than the camera. For
fast moving targets (in my case planes, cars, and bikes, sometimes
birds) AF-C together with 3D 51 Point Dynamic Area, and 3D-tracking
has proven to be quite successful. The only failures have been due to
me failing to hold at least one AF point on the target. I can suffer
from pilot error as much as the next guy.

For landscape I use hypoerfocal distance focusing, though sometimes I
screw that up.)

I think that this is where you replace "sometimes" with "mostly".

--
Regards,

Savageduck