580EX/20D fill flash

[amber65910]

Hey guys, I just got my new 580EX and have an early morning Mother/son shoot tomorrow. Any quick hints on how to best set my camera/flash for fill? I will be mostly in shaded areas. Due to the age of my young client I need the "easiest" way to get good exposure without alot of fuss. Im pretty sure that even my reflectors will be usless since I am going without a helper. If I set my camera on Manual mode the way I normally do, should the flash be set on ETTL, or manual? also should my camera be set to evaluative or average metering? Sorry if this seems to be a dumb question, but Im a little nervous since my old "backup flash" is being loaned out right now. Thanks!

[drisley]

The way I shoot, I set my camera in AV mode, select my aperture, and let the camera pick the shutter speed. But full manual is fine too.
I leave the ETTL-II setting on evaluative, but I've never tried average metering.
Then, I usually just dial down (I have a 420Ex with no full manual) the FEC to about -1 1/3 or -1 2/3.
Schmeolzel posted this link to a great PDF about fill flash that you should find very usefull.
http://www.popphoto.com/assets/download/821200311318.pdf

EDIT:
I just found this explanation of the ETTL-II evaluative and average modes:

"IIRC, almost all E-TTL II bodies offer two modes of flash exposure: averaged, and evaluative settable by CF (the exceptions may be the Rebel XT/300X and 350D, which I think default to evaluative). With evaluative metering, backlit conditions are detected, and the flash exposure emphasises those areas of the image that show significant changes of illumination with the preflash, whilst downplaying any areas that are too reflective. With a distance reporting lens, the algorithm also adjusts exposure with a guide number calculation based on focus distance as an additional factor, provided the flash is not in bounce mode and is either shoe mounted or on the OCSC 2. Thus fill flash under a hat brim should in theory work well. In practice, some wedding photographers find that Canon's algorithm needs adjusting by say +2/3 FEC - but this is consistent. Some owners have found it necessary to have Canon recalibrate flash metering, but when this has been done, it works well."