Noons wrote:
David Farber wrote,on my timestamp of 17/09/2008 9:01 AM:
I was wondering about how fill flash affects the existing light. Of
course it will take the shadows and lighten them up a bit, but what
about the parts of the picture that are correctly exposed by the
existing light? I mean the light emanating from the flash (attached
to the hot shoe) does not just go to the shadows. Wouldn't the areas
not in shadow then be overexposed by a half stop? My fill flash
photographs (from print film) have been coming out nicely but this
conundrum has me scratching my head. On second thought, should I be
using some ratio method to compensate for the existing light
exposure or is that not how it's done? I'm using a Minolta Maxxum 7
with a 3600HS flash unit.

What you forgot is why/how folks use fill flash.
Yes, it's additive. Have a look at most examples
in manuals for fill-flash: it's usually a portrait of a
person in shadow, with a light or shadow background,
AWAY from the main subject. That means if you shine the
flash at the subject, it'll light it up ok but the
background will be too far away to be seriously influenced
by the amount of flash light used.
Flash lighting is very dependent on distance from the flash,
given constant intensity.

Thanks for pointing this out. I use fill flash mostly outdoors where there
is a bright sun and harsh shadows. With the sun high overhead, the light is
not even in the same direction as my on camera fill flash. I think just
taking more pictures, taking good notes, and experimenting more will help me
understand this subject better. With all the options on my camera, I
sometimes pay too much attention to the numbers and start missing the good
shots.

Thanks for your reply.
--
David Farber
L.A., CA