Image stabilization panning detection in RF lenses

Duckman21 wrote:

On Canon forums I received confirmation from a Canon product expert that there should be panning detection built into the 800mm f11 and that it is most effective with Electronic First Curtain Shutter. For my usage of BIF and swimming birds, however, I don't find it particularly helpful and have been getting more keepers with it turned off. I find it better to use electronic shutter because at least you can maximize your chances of having at least a few sharp shots.

I'm guessing the issue would rather be how much speed is needed to stop horizontal stabilization, slow-flying/swimming birds probably won't cut it.

Another possibility is that you are not allowing enough time between half-pressing the shutter to activate IS, and completing the press to take the shot(s). I don't think Canon publishes an actual time, but it might be around half a second. That's easy and comes very naturally when taking static shots with IS, but more difficult to coordinate when taking dynamic shots such as panning.

If you take the shot before the IS is ready, it can actually add to any motion blur instead of cancelling it out.

Try tracking the bird with a half-press, then after a couple of seconds watching the focus points - which will hopefully settle on the face/eye - complete the press to take a shot or a short burst.

Having said that, many people advise turning off IS for birds in flight, even with lenses which have a switchable Mode 2.