Canon Speedlite question

the_manchine

Is it possible to disable the actual flash in order to use the IR just as an assist for the auto focus in low light conditions?
Don't think I can do it on my 420EX, just wondering if it can be done on the fancier models.

King Eric

what kind of camera do you use?

in 20, 40 and 30d afaik there is a custom function to stop the flash firing

in the 580 ex there is a way of fooling the camera into not fring the flash too
if you change the flash mode (in the flash's custom functions) i think to ttl instead of ettl the camera won't trigger the flash pulse because it thinks the flash isnt compatible

a quick yahoo should throw some threads on photo.net etc up

City-Exile

Never tried to do it, to be honest.
There's a lot of controls on the 580EX II though.
I'm sure you could get a copy of the manual online somewhere.

Calina

What camera do you have?

On the 40D if you set Flash firing to disable, the flash won't fire so you just get the IR assist for the AF.

Fajitas!

As Calina said.

the custom function no. differs from body to body, but it's there!

the_manchine

Got a 400D. Never thought it'd be a function of the camera. Must dig out the manual.
Ta for the replies

Fajitas!

Ah. Actually, not so sure on the 400D, thought you were using a 40D, but got confused with that Calina had said.

the_manchine

Curses, foiled again.

Will have a look in the manual anyway just to be sure.