> Date: Thu, 18 Mar 1999 08:13:07 -0500
> From: Thierry PERTUY <[EMAIL PROTECTED]>
> Subject: RE: F100 and flash questions [v04.n310/21]
> Message: 21
>
> > The pre-flashes are used to detect highly reflective surfaces in the
> > image (like mirrors or white walls) that aren't lit by the ambient
> > light. If you bounce the flash, you'll have to compensate for those
> > yourself.
>
> Ok. Will do but I don't understand why the pre-flashes couldn't work with
> indirect flashing.
>
Because the preflashes also work in conjunction with the "D"
lenses -- the distance information from the lens, plus the
known power of the pre-flashes provides a way to gauge the
lightness/darkness/reflectivity of the subject.
Once you tilt/swivel the head, the preflashes are turned off;
they couldn't possibly be useful because now the distance they
travel is unknown -- let alone what type of surface they're
bouncing off to hit your subject and bounce back into the lens!
Chris
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