Example: Isolation versus
Prepared 2007-07-07 by Bill Claff
D70 with 70-180mm micro-nikkor
@70mm f/11 1/250s
@180mm f/16 1/250s ISO 200 2 SB-R200s
@180mm f/16 1/250s ISO 200 2 SB-R200s and 1 SB-800
Top image shows even ambient lighting.
Bottom left is "normal" flash on just the subject.
Note "black" background isolation.
Bottom right is flash on subject and flash on the background.
Note the "normal" appearance with no black background isolation.
Still isolated by Depth Of Field (DOF).