In a nutshell, the pre-flashes are designed to tell the camera something about the reflectivity of the scene being photographed. In order to do this, it has to make use of some distance information-- otherwise it couldn't tell any difference between a dark object right in front of the camera and a mirrored surface much further away. If you bounce the flash, there is no longer any relationship between the distance to the subject and the distance the pre-flashes have to travel, so the camera can't extract any information from the pre-flashes. >Date: Thu, 18 Mar 1999 08:13:07 -0500 >From: Thierry PERTUY <[EMAIL PROTECTED]> >Subject: RE: F100 and flash questions [v04.n310/21] > >> 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. > >Thierry
