Focusing advice (1DN) for in flight birds with BG.

In flight birds against a background, I just can't seem to be able to perfect a way of at least locking the focus on the subject for more than just a short amount of time if indeed any amount of time!? I'd be gratful for any advice anyone could give me on perfecting my technique for such occasions and also which settings (if any?) I might change in camera to provide more of a chance of keeping the focus locked on the subject? Trouble is aside from gulls and a few others over here in Guernsey most of our birds are on the small side which I guess doesn't help matters?

Should I be using the centre focus point only when background becomes an issue?

For in flight shots I usually use either the Canon 300 2.8 hand held or the 500 f4 and side kick.

Many thanks in advance.

Paul
Guernsey, Channel Islands

i know what u mean, its especially hard to keep the head in focus and not just the body as well. I find using a gimbal helps for anything heavier than a 300/4 or a 400/5.6 Not sure if the sidekick is the best option for a 500 panning as its desgin means panning can be quite stiff at times.

Paul,

I don't have any experience with the 1D IIN but I guess the principal and techniques are similar no matter what body is used.
I find multiple focus points can work ok if the bird is against a completely plain backdrop,such as sky,but with a detailed background I'd be inclined to manually select the center focus point in that situation.

It's widely reported that having Image Stabilizer turned off can speed up initial focus acquisition,if you wasn't already aware of that.

Shooting birds in flight and getting a high percentage in focus in not easy; shooting small birds in flight is very difficult. To be successful you need certain things to come together and without this, it becomes an exercise in frustration. The things that need to come together are: regular and more or less predictable flight path, light direction, wind direction, absence of background clutter, a position that allows you to track the subject in to the window where you want to shoot. Obviously, for frame-filling shots of small birds, you need to be pretty close as well. So flight shooting is more of a place thing (a result of careful site selection) rather than something that is related especially with what parameters you have set on the camera.

If you can track the bird with the centre focus point then this is ideal. What you place the focus point on will be in focus. For birds which fly erratically, this is very difficult to do. In this case, use the automatic focus point selection option (the so-called "ring of fire"). To use this successfully, it is important to remember that what is first acquired by the AF system (usually the centre point) is what the camera will attempt to lock onto. You should definitely have the AF 7-point activation CFn-17.1. With the ID2N and the 300/f2.8, this gives you a cluster of 7 cross-type AF sensors.

Thanks everybody, very helpful. Over the weekend my mission is to try and get a swallow in flight, so I'm diving straight in at the deep end Over the last few days I've been going about it pretty much exactly how Phil has described above so it's good to know I've been on the right lines.

Best wishes.