Capitalize At The Clock Tower, Ottawa, ON

I have never shot snowboarding and this Saturday and I will be going downtown to shoot a competition. I like snowboarding so I thought I would give it a try. I will also be borrowing from my college a 1Ds Mark III with a 200mm f/2.0 lens and 2 580 speedilights along with a 16-35 f/2.8 wide angle lens to put on my own 50d body. This is what the event will be like:

http://www.youtube.com​/watch?v=6z_GS2kw79w

I have not used a flash before so I would like to know how to use it and what setting I should use when I am there. Thanks.

Edit: Shoot, I just noticed that I should have posted this in the discuss sports thread. Sorry.

Anyone?

Bump. Please, I need some help. I don't want to post this in the other thread either and end up flooding the boards.

Minimum of 1600ISO, If you haven't shot under these conditions than you may find it difficult, I would say just put it in Program mode and let the camera make the selections for you, but your pictures probally will come out blurry, When shooting action I find anything under 1/500th and your run into some type of blur.

You'll just have to experiment.

If you going to use the flash, just stick it on top of the camera in ETTL mode, and shoot in M. The ETTL should get you a reasonable exposure on your subject. Set the camera to settings that give a good looking ambient exposure and shoot away. The duration that the flash will illuminate your subject will be very short, and should be able to stop motion.

So ISO 1600 and 1/500 with E-TTL for the flash would most likely be good? I will probably mess around first.

THIS IS ABSOLUTELY URGENT NOW!!! PLEASE HELP!

Okay so I brought home the Mk III and 580 EX Flashes....I have no clue how to use the flashes or the camera... Everytime I go to take a photo, the motor drive just sounds in the lens and no picture gets taken. Which settings should I have on the flash?? I have it on ETTL, but I don't know what the other stuff is for. Please please help me out. I also need to know how to change the camera mode on the Mk III. (Continuous, Single, etc.)

EDIT: I figured out most, but now I need to know how to change the aperture and the focus points and how to move it over and such. I am looking online, but I can't find anything so I thought I would ask here.

If your talking about what I'm thinking what's happening (and don't quote me on this) is that your camera isn't taking a picture because it can't find the right exposure. Does it keep zooming in and out and the flash keeps making those flash burst?

I'm still reading up on my manual and other things. It's best you do the same. Good luck.

It's a fixed 200 so it won't zoom. I actually figured out the problem. All I need to do now is figure out how to move and change the focus points.