Using Canon; 6D, 2 600 EX-RT, one on camera and one OCF in group mode, and I have a 580ex 2. I would like to use the 580 ex in radio mode also, since optical at receptions and events is dodgy. Is there a trigger I can attach to the 580ex that will work with the EX radio signal from the 600 ex? In other words is there a receiver that hot shoes with the 580 that receives the 600 signal. I know I may lose the group mode on the 580 and may use it in ettl or Manual but that’s ok. The important factor is using the radio signal WITHOUT a separate transceiver, and that is compatible with the 600ex so I don’t lose capability of group mode. I know Youngnuo makes a transceiver/receiver combination, and I have a set from Phottix but they negate ETTL, and I don’t want to use a separate transceiver anyway. Just trying to find a way to get the perfectly functioning 580 in the mix. Thanks y’all in advance for your replies!