Canon EOS R6 + Canon RF 800mm f11 Auto Focus Speed Accuracy And Subject Tracking

A question frequently asked is how good is the auto focus of the Canon EOS R6? Especially when paired with a small aperture lens like the f11. Combine the small aperture with super telephoto focal length of 800mm. It would mean the auto focus algorithm has to be pretty good. By that I mean the speed with which it acquires the initial focus, and then how good it is at sticking and tracking the subject. I recently put this to test by attempting to capture swallows in flight. Swallows are small birds. They fly fast. They do not seem to have a fixed pattern and turn and swoop and dive and ascend with their beaks open to swallow flying insects. 

I was pleasantly surprised the Canon EOS R6 did very well. The Canon EOS R6 with the RF 800mm f11 acquired the auto focus quickly. More important the auto focus was accurate. And then stuck to the subject like glue. The subject tracking was accurate and kept the bird in flight. didn't matter whether the swallow was flying towards me, diving down, ascending up, turning left, turning right, dive turn, ascend turn. No matter which direction the movement occurred, the Canon EOS R6 + Canon RF 80mm f11 kept the bird in focus. The eye detection is accurate. 

Managed to get a lot of keepers of the Violet Green Swallow's in flight. As long as there is an eye, no matter that of a tiny bird with erratic pattern, and swift movements, the Canon EOS R6 + Canon RF 800mm f11 got it and was accurate and tracked the subject well. Below are some low resolution photos. 

Location: Alex Fraser River here in suburbs of Vancouver. 

Despite the focal length of 800mm, had to do fair bit of crop due to the tiny size of the swallows. In real life, to my eye the birds look like darts. While I could see the dart like flying objects, I could not see the flying insects at all. The camera did though. In the second picture the swallow headed to swallow the insect (pun intended). I could not see that when shooting. It was only at home when converting RAW to JPG did I see the insect. 

Is there anything to keep in mind? Yes - the (MFD) minimum focus distance is a bit on the longer side at 19.69 ft / 6.0m. Which means although rare, you may miss capturing a friendly bird who dares to get closer than 20ft. Is the aperture of f11 something to be concerned about? In my real life usage the pro's outweigh the cons. It is lightweight. The Canon R6 even at high ISO produces clean images. The Auto Focus can keep up in  all kind of light conditions. So in my usage the only thing I wish was different was the MFD was a bit shorter. I have missed a few birding opportunities. These are only a few times. So again in real life not a show stopper. 

Conclusion: Canon EOS R6 is amazing camera I love it. I have the Canon RF 100-500mm L lens. Yet there is a place for the Canon 800mm F11 in my lens keepers. Would I recommend this lens? Yes I recommend this lens.