Four hours behind the lens on the 1D3 yesterday, shooting our swim team's action shots. 2857 shots, ~70 swimmers. 95% laying on my stomach on a Thermarest on the deck. I had a bean bag under the 70-200 tirpod mount, which made this position much easier. (litterally, I filled a ziplock bag with beans before I left the house --- last minute idea) It was a blast, but I'm a bit sore.
One note on AF settings: they ROCK on this body. Man what a great help! I read through Canon's "Guide to AI Servo AF Custom Functions
" a few times since I've had the body. When I was on the deck, I was able to quickly change C.Fn III-2 once I missed focus on some slower swimmers (under water too long). It fixed me right up.
Hopefully I'll have some shots up in here soon (obviously have a lot of culling and post work ahead of me). We raised > $1800 for the team in 4 hours though (well, not counting upcoming post).