This question concerns the use of multiple wireless flash groups with the Elan 7. The recent discussion on this topic debated whether or not the Elan 7 supported mulitple wireless groups with the 420/550EX/ST-E2 system. The reason for the uncertainty arose from the chronology of the manuals for the flashes and the camera; there seems to be no clear "yes or no" answer in Canon's manuals. My educated guess is that multiple flash groups are not supported by the Elan 7; only by the EOS 3, 1V, and 30. The camera is intimately involved in determining exposure for groups A and B, commanding an exposure measuring preflash for each of these groups. The camera has to have extensive logic (via firmware), and the necessary speed of processor to support this. I posit that Canon decided to leave this feature out of the Elan 7. The fact that the Elan 7 manual does not mention groups when discussing wireless flash suggests also that they are not supported. On the other hand, it appears from the discussion that if you mount a 550EX on an Elan 7, the 550EX allows you to set an A:B group ratio. The designers should have locked that out if the Elan 7 doesn't support multiple groups. (BTW, does the Elan II lock out A:B ratio setting on the 550EX? It is locked out on my Rebel G.) I know that some readers have experimented with the Elan 7 and wireless groups, but I'm not sure these experiments are definitive. One kind of definitive experiment would be to determine whether the preflashes from groups A and B were concurrent or successive. Concurrent-->no subgroups; Successive->subgroups. Has anyone yet obtained definitive word from Canon on this? Of course, if subgroups are not supported, you can do what I did with two 550EX's and the Rebel G: Flash exposure compensation set at each flash. Not possible with 420EX's, but doable, with limitations, with a 550/420 combination. DGW * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
