I've shot some weddings using a Canon 10D and Canon EF 24-70mm 1:2.8 L USM lens and a 420 EX Speedlite with a So-Fen Omni-Bounce diffuser. A photographer I respect, one who used Fuji equipment, recommended that I shoot indoor reception shots at ISO 800, daylight white balance, 1/30 sec., metering to expose for the background and letting my Speedlite light just the subject. He gets great shots that way. But when I've tried it, I get terrible results. At 1/30 sec. my pictures just aren't sharp, and at higher shutter speeds my backgrounds come out too dark. Frankly I get better exposures using my camera in Program mode. But I would like to hear what indoor settings you shooters with similar equipment recommend. I've read the excellent information about using flash with EOS, and now I'm looking for advice from practical experience.