Zeee wrote:
Karl_Guttag wrote:
Zeee wrote:
Karl_Guttag wrote:
Zeee wrote:
All those airplane model shots were take with IS in mode 3 if anyone is interested.
Why did you use IS Mode 3?
It does not kick in until the actual exposure, IS can interfere with AF when tracking.
That is a surprising comment. I think most people (and according to the manual) would use IS Mode 2 when tracking. Did you find that Mode 3 worked better for you than mode 2?
The manual does not say that specifically but if you do some searches on the subject you can get mote details. It's really hard to judge. Just like the first time I used Servo I had to learn to trust the process. They have been putting mode 3 in lenses for long time and continue to do so. If it didn't work Canon would have stopped adding that feature I would think.
From the manual

Mode 3 is especially useful for sports photography where you are likely to be moving between subjects quickly. In IS Mode 1 this can create a bump or jump within the viewfinder as the IS races to keep up with the lens movements. Instead, by not activating until the shutter button is fully pressed, it saves the system trying to compensate for random, rapid lens motion and compensates only at the point you are taking an image.
Also, by limiting the activation to the point of capture, it ensures that the stabilisation group is centred within the barrel, therefore offering the maximum degree of stabilisation.
Source
https://www.canon-europe.com/pro/infobank/image-stabilisation-lenses/
I also find electronic shutter and H+ to help with tracking. I find with this combination in with IS Mode 2, the AF keeps locked onto the planes. My main worry is motion blur at shutter speeds between 1/60th and 1/125th at focal lengths typically between 150mm and 500mm (and sometimes up the 700mm).
I seem to find that if I used EFC shutter, the AF tracking was not as good as it was with the electronic shutter. I assumed this was due to the shutter interrupting the sensor's view.
I briefly experimented with hand holding with a long focal length in mode 3, I found the view through the viewfinder to be very jumpy, making it hard to track the plane. But I only tried it for a short time before giving up.