All TTL ambient metering is based an assumption of reflectivity of the subject. The pre-flash is done to actually measure the reflectivity on the camera's axis, of the flash. It's as good as you can get without and incident reading flash meter. BTW, there are a number of situations where pre-flash may have to be turned off. A flash meter will be tripped by the preflash, and measure the main flash. Reflectors and diffusers may also foul things up.
BR Lon Williamson <[EMAIL PROTECTED]> wrote: > >Wouldn't it be possible to compensate for ambient and >put out the right amount of flash based on distance >alone? __________________________________________________________________ McAfee VirusScan Online from the Netscape Network. Comprehensive protection for your entire computer. Get your free trial today! http://channels.netscape.com/ns/computing/mcafee/index.jsp?promo=393397 Get AOL Instant Messenger 5.1 free of charge. Download Now! http://aim.aol.com/aimnew/Aim/register.adp?promo=380455
