Question about off-camera TTL flash slaves

Hello,

I'm starting to put together my own kit and I would really like to play/experiment with the off camera flash capabilites with my 40D. I've been reading about the capabilites of the EOS flash system especially in TTL modes.

In reading about the e-TTL functions when using off-camera flash. It's stated that you can specify a flash into one of 3 groups (provided you're using a 580EX as your master) A / B /C. You can then control the power output of groups A / B / C.

My question is how many flashes can group into each group?

Is it possible to have two or more flashes fire with the B group designation? Or the C group? Or does the ABC grouping limit you to only 3 flashes - one per group?

thanks in advance.

cjcastan wrote in post #5238098
how many flashes can group into each group?

As many as you want.

As long as the slave can "see" the command flash from the master, it will fire.

OK cool.

But each flash in a group would fire at the same power, correct?

Thanks for the quick reply.

PS. Hey I see you're from the chicago area? Me too. I'll have to check out the POTN events sometime.

cjcastan wrote in post #5238210
each flash in a group would fire at the same power, correct?

Correct.

Be sure to read the E-TTL wireless flash tutorials here:
https://photography-on-the.net/forum/showthre​ad.php?t=138907

Click the link in my sig. That page explains how to get on an email list so we can keep you in the loop!