My RX10IV can produce fantastic results. But it also seems to miss focus sometimes even with apparently simple subjects like perched birds. This could of course be technique on my part. I thought of getting it professionally checked out but the quote for that at the official Sony place is in excess of $400 and that’s before anything is even repaired. I want to do some controlled testing. I’m going to set up some tripods with stuffed animals and such for static but how would folks go about testing focus for moving subject? My first thought is to tie a stuffed animal to a rope and hang from a tree and have is swing around. Looking for ideas.