20D Custom Function 17: #4 One Shot --> AI Servo?

[shiningstardv]

I have (what is probably a really stupid and obvious) question regarding custom function #17 on the 20D. I have enabled choice #4, which allows you to switch instantly between the One Shot focus mode and the AI Servo focusing mode. However, I cannot for the life of me find the button which makes this switch.

I have searched the manual and the forums, only to find nothing. Any help is greatly appreciated, as this is a feature I would find very useful. Thanks!

[Chazs]

I think I found some info for you. Here's a quote:


17. Lens AF stop button (AF stop, AF start, AE lock while metering, AF point: M-->Auto/Auto-->Center [for changing the focus point], One Shot <--> AI servo, IS start) - this button is only found on super telephoto lenses

Looks like you need a "monster" lens for this function to work. Hmmm. Here's where I found the quote:

http://www.dcresource.com/reviews/canon/eos_20d-review/index.shtml (http://[url=)

[ENikS]

Page 146 of user's manual states: The AF stop button ip provided only on super telephoto lenses.