Так многие об этом мечтают:
http://photonotes.org/articles/eos-f....html#wireless
"Unfortunately no current EOS camera can use its internal flash unit as a wireless E-TTL master; convenient as that would be. Hopefully future EOS camera bodies will have this ability - it shouldn’t require additional hardware to implement, and it'd be very handy. You would then, for example, be able to walk around with a camera in one hand and a flash in the other without any bulky transmitter units or cumbersome cords."