I've just been using manual exposure and I'll set the Shutter speed to either 1/60 or 1/125 and the aperture to the largest aperture (usually). They come out perfectly every time. If I'm working with really high ceilings (12ft or so), I might have to bump the ISO up to 200 or 400 but that's the only catch.
Here's a shot I took yesterday. I just pointed the 580EX straight up at the ceiling and snapped.
I have a G1 coming and hope to use it on an assignment a week later at a church Vacation Bible School. A flash will be needed and there really isn't time to get a dedicated flash for the camera. From my reading, the Metz 48 AF seem to be the best match. All of the best matches are larger than the camera, and it seems that choosing a flash on size isn't the way to go.
You use the Canon 580, and I plan to make some tests with the Canon 580 II. You said that you just use manual, but I hope you could be a little more specific since my time is getting short.
1. In manual mode, do you try to set the exposure correctly for the scene?
2. Do you set the 580 to ETTL?
Thanks
Wil