Here is my question.

I have a 40d and one 580ex2 and one 580ex. I know that I can adjust the 580ex2 through the camera controls. IF I were to have 2 580ex2 one master one slave both in manual exposure would I be able to control the power output of both through the camera controls on the 40d or just the one on the camera?
I haven't been able to find that info anywhere. I know it will control the ttl output but if find that off camera flash is not to accurate with ttl. So I am interested in manual mode.

thanks,

Greg

Sorry, I shoot Nikon so I'm not sure. Is there a flash controller built into the D40? If so I'm sure that the master flash in the hotshoe has a controller mode and that the off camera flash can be set to a slave or remote mode. Then you should be able to control the second flash from the master flash.

Hope this helps, Kirk

It seems you have not read the manual, I have not too , i learned from a friend, jeje

but to make it easy
1-press the zoom button for about 3 seconds
2-you will have the menu for master or slave
3-use one in master mode(the one in the camera)
4-the other in slave mode.
give them a try
I use them in ETTL
make sure the slave IR's looks toward the master

try it and let me know