Canon 7d AI focus (1 Viewer)

Does anyone use the AI FOCUS method instead od one shot or servo. Are there any advantages or disadvantages with using this, i.e. is the focus as quick and as accurate ?

AI Focus is generally recognised to be the best option if you like your images blurry. It seems to combine the worst aspects of both One-Shot and AI Servo. I stick with one or t'other.

Somebody will be along very soon to explain how moving the AF function to one of the back buttons can give you the benefits of both modes without having to switch. Personally, I find I've not got the coordination to make it workable.

Intersting to note that it doesn't exist on a 1D series body, well not on my MkIII anyway. Might tell ya something.

I can think of no useful purpose served by the AI Focus mode and I have no idea why Canon includes it on any of their cameras. I really wish I could disable the mode altogether, just to avoid switching to it by accident.

If you take a look at the videos on the B&H website by Canon about their AF system I think you'll find that even they caution against its use.

Search here for "Canon autofocus" - http://www.video.bhphotovideo.com/ - and then start with Part 1 of 3 of "A Look at The Canon Autofocus System". The first couple of minutes is a struggle to get through but persevere and you may find something useful there.