No 7D BIF AI As Yet?

Started Sep 27, 2009 | Discussions thread
Chris R-UK Forum Pro • Posts: 23,260
7D BIF with busy background - images

I took my 7D to Gigrin Farm in Wales yesterday to photograph the Rek Kites that are fed there every day. Here is an overview shot taken by my wife:

These shots were taken from a hide about 50-75m away from the action. The background is a mixture of sky (very grey yesterday), trees and farmland.

Since people on this thread are interested in the 7D's AF performance against a busy background, I will concentrate on that.

I tried out all the focus point options except Spot. I particularly tried all the options against trees because that was the main problem that I had previously when using a 20D at the site. I was using a 100-400. I had AI Servo Tracking Sensitivity (C.Fn III-1) set to -1 (range is -2 slow to +2 fast) and AI Servo Tracking Method (C.Fn III-3) set to Continuous AF Priority.

Here are some shots taken against trees:

ISO 800 1/1250 f5.6

ISO 400 1/500 f6.3

ISO 800 1/1250 f5.6

I took these as JPEGs because I didn't want to have to review 480 images in DPP! No PP except cropping.

I took 40 individual or bursts of shots (I am counting 1 burst as 1 shot) against trees with the following results:
Focussed on bird: 23
Focussed on trees: 7
Focussed on neither: 10

Not all of these 40 are sharp at the pixel level, but the shots above are all pretty sharp.

In general all focus point options seemed to work although I preferred All Points or Expanded Centre Point. I don't think that any one method gave better results than any other.

Here are two more against different backgrounds:

ISO 400 1/500 f6.3. As you can see, this bird has been tagged.

ISO 400 1/500 f6.3

I hope this is useful to those of you concerned about AF.
--
Chris R

 Chris R-UK's gear list:Chris R-UK's gear list
OM-1 Olympus E-M1 II Olympus M.Zuiko Digital ED 9-18mm F4.0-5.6 Panasonic Lumix G 20mm F1.7 ASPH Olympus M.Zuiko Digital 45mm F1.8 +3 more
Post (hide subjects) Posted by
Eug
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow