yeah henry i totally agree and i see your methods. the reason why i do so is because my long lens is HSM and my short lens is not, so it isn’t that good @ AI Servo. Plus i also usually shoot surfers with my long lens and i need to track all the time.

@Aaron C That is funny ’cause I actually use it the opposite… Servo for short lens with flash and AI Focus for Long lens… The reason is because you want to tract your celebrity when up close and personal… When you are shooting long, the celebrity is usually not going anywhere and therefore you can lock.

eos 50d. i only use servo on my 120-400 sigma but with my 18-200 i always used to use AI Focus, but now i’m certainly using one shot focus from now on with that lens.

@Aaron C … What camera where U using??? On AI Servo, depending on the camera, you should also get it to fire rapidly… Especially with a power pack.

hey guys, …. i recently got myself a 580exii speedlite and i love it – naturally. but for a long time i haven’t been able to figure out how to shoot with it really fast continuously on ETTL, until yesterday! it turns out that AI FOCUS was slowing it down because the focus was constantly monitoring subjects and making the flash hesitate. by using the ONE SHOT drive mode i was then able to use ETTL and get a flash in every shot! i hope someone finds this useful! cheers!