I just got my 420ex two weeks ago, so I'm no expert. I did try
flash fill outdoors, though. If the 420ex is on the camera and
turned on, you've got flash fill. Just adjust the amount of fill
to suit your taste with the flash adjustment on the white balance
menu. I thought it would be harder than that. One photo I took
was at a local college. There's a porch with a very tall arch. I
shot through the arch towards another building. The inside of the
arch was too dark, so I fired up the 420ex. It worked great!
Added just enough fill to bring out detail without looking obvious.
Good luck,
Doug
Who knows how to use an external 420ex flash for outdoor fill with
the G2? Normally you can use the flash mode selector to force the
flash on for outdoor fill. When a 420ex is mounted on the camera,
you can't change the flash modes for forced on operation. How does
one use the flash for fill outdoors?
Mark