Sony A7R4 A7RIV quick autofocus video test
Had my 7 year old dance the best he can and took a couple of short videos to see if A7R4 can keep up with him.
I plan to do the same type of video later with my Canon EOS RP.
To me, A7R4 did good but not sensational, I have a feeling both EOS RP and Nikon Z6 (unfortunately I don't have Z6 on hand anymore) do somewhat better. I have sample videos here of both Z6 and RP with my wife dancing, but obviously they are less spirited that the ones from my kid
I used 35 1.4 Sony Zeiss wide open at 1.4
• NIKON Z6 VIDEO SAMPLE WITH 50MM 1.8S Z6 video
• CANON EOS RP 1080P 60fps Handheld Video S... EOS RP video