Turning off the 580ex

I was using my 580ex on the camera and 550ex on a light stand. I wanted to just light the scene with the 550ex on the stand and use the 580ex to trigger it, but I couldn'r figure out how to turn off the 580ex.

I read the manual and did what it said but, it still kept flashing. What am I doing wrong. Has anyone tried this and been successful?

Help.

Yeah I manage it sometimes, with the manual in one hand and the 580EX in the other. It's a pain in the arse, but it is possible. Make sure your 550EX is on channel B, the 580EX is on channel A, then have a play. Take another look at the manual, if you figure it out let me know! If not i'll have a bit of a play myself, it's something I should know how to do in 10 seconds or less.

The alternative is to set the ratio to 1:8, that way very little light comes from the 580EX, and is much easier to do.

I think your seeing the preflash on the 580ex....

Yeah good point. In wireless ETTL I think there's a bunch of preflashes, it can still go off even if it doesn't contribute to the lighting of the scene.

This may not directly help but on the 550, when used as a master the flash can be switched of by repeatedly pressing the SEL/SET button, which scrolls through options including RATIO and CHANEL selection - and also includes "Master Flash Off" - which is the setting you are looking for.

Does the 580 have a similar setting to this that you could try?

Or, failing that, if you are not relying on it to produce output, why not switch flashes, and put the 550 on camera - as a non-firing master, and set the above option to fire the 580 as a slave? Might actualy give better results??

580 and 550 can do pretty much the same thing with the same amount of power, the 580 is generally easier to use. I just have to read my manual to work out how to turn the master flash off, it'll be similar to the 550.

jj1987 has it right...

Page 36 of the 580 manual describes the action to take to turn off the master (580), leaving the slaves to do the work.

I forgot about the pre-flash... Thanks

I just tested with a few shots and it seems to work. Even though there is a pre-flash, it doesn't seem to affect the photo. Thanks again everyone.