How I typically shoot in a similar situation is to keep the camera in
M mode so the shutter does not drag and blur becomes a problem.
My starting baseline is ISO 200, 1/125th and f/5.6. I adjust as
needed from that baseline. 1/125th ensures there is no shake with
the 24-70mm I usually use with flash and f/5.6 is a good compromise
between DOF and the amount of flash power needed.
Unless there is a compelling reason to do otherwise, such as a wide
establishing shot in a series I like to fill the frame with the
subjects in the foreground and let the flash fall off to contrast and
separate them from the background clutter. It's a matter or person
taste and in part due to the fact that I am old school and really
don't mind if a flash shot looks like it is a flash shot if taken
indoors.
I use two flashes whenever possible. I keep my fill on a bracket
over the lens with a diffuser, and my off camera light is on a
modified IV stand - five compact legs with wheels make it effortless
to maneuver, even at a party as these shots illustrate:
http://super.nova.org/MAG070128/
The room was very dark so capturing much ambience was not an option,
so having two flashes added some punch to the lighting. The stand on
wheels is what makes the two flashes practical. Credit Monte Zucker
for that brilliant idea - I learned it from him 35 years ago.
The simplest approach with two flashes is to simply park the off
camera flash behind and to the side of the action being capture. In
fact in the 5th shot at the link above you can even see part of the
off camera flash in the photo. I left that one in because the lady
in it is a friend and its a funny candid capture of her.
When shooting without 2 flashes isn't feasible all it takes is a flip
on the switch on the base of the 580ex on the bracket from Master to
Off to be shooting in solo flash ETTL mode.
When there is a need for more ambience I will raise the ISO speed and
slow the shutter to what I think I can hand hold.
CG
