though I would start a new thread for this after hijacking this one a while ago:
I'm trying to work methodically through the various AF settings as I could never get AF to work well with BIF (Birds in Flight) in my garden. So please bear with me. For my tests I stood by the side of the road and using low-speed continuous shooting took shots as cars came into view and crossed the field of view. Most of them will have been driving around 30-60Kph.
I assume the Camera should be able to handle this situation. Agreed?
Lens is a 70-200 F2:8 L IS II USM (Group A), IS on set to mode 2. AF point selection set to automatic.
First point. If I set the camera to Automatic (A+), then it will focus on something nearby which is at the side of the AF points. See the picture Focus1. IMHO that is correct.
Now, if I switch to AV, now in AI-Servo AF, then it will only focus using the center points. I tried various Av and Tv settings, I could never get anything other that the center points to "Lock" (flash red). Picture Focus2.jpg. I was using AF Case 3 here, expecting
In Case 3, the [Tracking sensitivity] parameter is set to [+1]. As a result, subjects that come into the AF points will be focused on more quickly. This setting is most
effective when subjects appear suddenly in the frame (for example photographing skiers in an alpine skiing downhill race,).
I get the effect that it has locked onto someting in the background (Focus3.jpg) and does not change focus even if the car crosses in front of the object that was in focus. Plus, it never tries to follow the car anyway. See Focus4.jpg.
This was done with the three parameters set to default and then tried to increase Tracking sensitivity to +2 without any effect. Now as the AF wont follow a car, I'm not surprised that it doesn't follow a small bird.
I'd appreciate any hints of what I may be doing wrong.