Still Flash operation question

[goobersnuftda 0]

I have a 20D and will be mounting a 580EX to my camera helmet.

The flash will be mounted flat not the traditional "L" shape obvisously but the quesiton I have is the issue of the focusing transfering over to the IR sensor on the flash. What issues does this present for daytime/nightime free fall flash shots?

[linestretch 0]

I'm pretty sure the IR focusing only works in auto mode. In the other modes, it uses the focusing points inside the camera. My flash is mounted flat and the thought came to me too.

my pics & stuff!

[PharmerPhil 0]

The flash determines it's settings through the lens if you are in E-TTL mode (Electronic Through The Lens). However, to do this with the flash mounted remotely, you need to use Canon's off-shoe multi-pin connecting cord instead of a simple sync cord.

[AHoyThere 0]

I could be completely wrong, it's been a while since I've read the manual that came with the flash but, IIRC...

I think the IR focusing assist light will only activate during a low light situation. So, if your typical use for flash is for fill to elimiate shadows on a sunny day, it should not be an issue. This is what I typically use external flash for.

It also may not be an issue if you are using a fixed manual focus.

If you are using auto focus in a low light setting, then it could be an issue.

But you know what they say, when all else fails, read the book.
Good luck.

[Laszloimage 0]

I'm using the same flash but most of the time I set the falsh pwr manually. I wouldn't worry about the IR.
I tried the ETTL as well, it works fine, but I still prefer the manual settings.
-Laszlo-
check out my site for the pics I took with 580EX
(photos dated after Jan 5th 2006) www.laszloimage.com