EOS R1 Why didn't Eye Detection and Focus work?

[DhandaNot]

I am sharing a few of the images from a burst I took. The light is good, the flying bird is in front of the camera. However R1 (with EF 500 F4 IS ii with1.4 X IS iii) is unable to detect the eye and focus properly on the raptor. Some of the images show the focus obtained on the bird, but that too is not in focus.

What could be the issues here. I know the bird is not very big in the frame, However, I have seen the camera capture the eye at similar distances.

[Anonymous]

I'm sorry nobody else responded, don't know why. Unless you have a specific question about my answer I can't help you further.(I'm no expert but I've taken close to 450.000 shots in the past year with my R5II and R1, getting a good idea how they behave in most circumstances)

[DhandaNot]

I think "heat haze/atmospheric distortions" is the reason here. (Apart from other things mentioned) The shots were taken from a window of vehicle, in some cases the engine was on that would have caused some vibrations.

[Anonymous]

Certainly possible, I've had that several times(not anymore, got a EV) but don't underestimated how often it happens just above the ground with just a slight temperatue difference(it doesn't have to be warm). Just yesterday I was at the coast and saw several diving attemps from Sandwich Terns. From every sequence the higher up photo's were in focus and sharp, close to the sea still in focus but a bit blurry.

[Anonymous]

Just came across this, maybe it could help you, using a flexible/smaller zone(if you can keep it on the bird) might help the AF system focussing on the eye/head.

https://www.youtube.com/watch?v=eMnXSZRh3Bw