*sigh* Need flash help

hi, i read the Flash bible about this already and followed the instructions step by step however i am still having problems.

I am using two flashes, 580 EXII on camera and a 430 EX off camera. I am using them in Manual mode with the 580 ( by default in group A) and 430 in group B. I can adjust the manual exposure via the 580 or through my 40D fine. However, i only want the 430 to fire and just use the 580 as the trigger... Here's my problem, i have followed the instructions and turned off the 580 by pressing the zoom button on the flash till the 3 little lines in front of the flash emblem blink, then i toggle the flash to the "off" position. Eventhough, everytime i hit the shutter button the 580 still flashes. I ran through all Custom functions of the camera and the custom functions of the flashes, and i don't think i saw anything in there that would overide the flash from not firing.

Can anyone think of another reason this is happening, or something that i maybe overlooking?? I was able to do this just last night and i didn't change any setting from last night and now.... is my 580 EXII on the fritz?

Thanks
-Mike

What you're probably seeing is the 580's pre-flash. The flash still fires, but does so for exposure purposes and to communicate (it's love?) to the 430. The shutter opens after the 580 flashes so that pre-flash doesn't actually affect the exposure.

Confusing as the dickens if you ask me.

**** lol.. i was just comming back here to tell everyone to ignore my post... it was just the pre-flash. I guess i never noticed it before just now Thanks for responding so quickly n1as. that confuses me too.... wth are all the pretty red lights for then? i thought the units communicated via IR or the red lights....

-Mike

The flashes communicate using visible light AFAIK, the preflash contains in information that the slave flash uses.

Since a preflash does not fire when the flashes are in manual mode, that was not the preflash you were seeing. That was the command flash which the master emits to tell the slave at what power and when to fire. Just wanted to throw that out for technical accuracy.

Cool, thanks guys for clearing that up for me. At a point i was ready to take a hammer to my flash

Now i have a question though, lets say i were using an ST-E2 as a trigger and had the 580 + 430 off camera as slaves using manual mode. How does the ST-E2 communicate? I'm just asking cause my curiosity has been sparked

Thanks
-Mike

MikeKS wrote in post #5840370
Cool, thanks guys for clearing that up for me. At a point i was ready to take a hammer to my flash

Now i have a question though, lets say i were using an ST-E2 as a trigger and had the 580 + 430 off camera as slaves using manual mode. How does the ST-E2 communicate? I'm just asking cause my curiosity has been sparked

Thanks
-Mike

In front of the ST-E2, above the red plastic lens, is an almost black panel. If you remove that panel and use the ST-E2, you'll essentially be operating a little flash set to master with the main flash disabled and works just like, for example, a 580EX set to master mode with the main flash disabled. What that black plastic panel does is block off the visible light so that only the IR light gets through it. The slaves can see the IR lights just as well as they can see the visible light so they go on working even though you yourself can't see the IR light being emitted through that panel.

Actually, technically, the slaves aren't really seeing the visible light even when the master is a flash because the slaves also have a black panel in front of its sensor which blocks off the visible light and only let the IR light in.

PacAce: Man you really know your stuff! How did you get so smart anyway?

queenbee288 wrote in post #5840694
PacAce: Man you really know your stuff! How did you get so smart anyway?

I ate all the green veggies my Mama told me to eat when I was but a wee baby.

Thanks PacAce

I ate the green veggies my mama-dukes told me eat... but all it did was make me poo a lot

-Mike