I have an R6 camera with a R 100-500 lens. When I am trying to photograph birds in flight against a blue sky, often the bird moves out of the focus box, at which point the lens focuses to a distance very close to the camera, thus the bird is totally lost in the view finder. I must then point the camera as some distant object (horizon for example) to get the focus back to where I can see the bird. So, my question is, can this behavior be changed? I would like the camera to focus at infinity when the autofocus loses its lock.
I thought of this, but since I am typically moving quickly between birds in flight and birds in the trees, this does not work well. Might be the only thing that works though.
Not sure if this will help you, but it's the way I have our R5 and R6 set up. I seldom have the hunting issue you are referring to, but it does happen. First, make sure tracking is set to Animals, and obviously enable Servo, which I have assigned to a button so I can switch from One Shot for perched to Servo for BIF quickly. I disabled all but Face/Tracking, Spot, Zone, and Large Zone in my "Limit AF Methods" (AF 4 Menu). Sometimes I drop Zone, it just depends on how big the birds are and their flight patterns. In "Customize Dial" (C. 3 menu), I assign the lens ring on the RF 100-500 to switch AF zones, that way I can hop back and forth from perched birds (Spot AF) to BIF (Face/Tracking or Large Zone) fairly fast, if need be. I leave the ring rotation at Default (clockwise) which allows me to turn it left, 1 click to get Face/Tracking, and 2 clicks to Large Zone from Spot AF, which is where I start by default. I mostly shoot using Spot AF unless I'm specifically targeting BIF. You can also set your MF ring to Fast, so if focus gets stuck in an area you can quickly force it closer to where you want to be. Usually, when I do this, focus locks back on.
I like the approach. I had not considered using the lens ring this way. I will have to try it. I also did not know you could change the speed of the focus ring, I'll try that too. The suggestion above of the focus limit switch also helps, I had forgotten about that. I tried it, and if the bird is not too far away it works, at least I can still see the blob once the AF misses, so I can reacquire fairly fast. These taken together sound like a good way to go.