----- Original Message ----- From: "Mr. Bill" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, February 29, 2004 11:08 PM Subject: Re: EOS Bill Maxwell's HI-LUX enhanced screens
> 1) I though EOS metering sensors were in the bottom of the film chamber > with the light path going through the main mirror and off a secondary > mirror hinged behind it. That seems to be the way it is in my EOS 5. > If this were the case, the focusing screen you use would have no effect > on exposure. > > 2) Any "brighter" focusing screen trades brightness for the ability to > manually focus. A brighter screen passes more non-image forming light > through to your eye, rather than capturing it to focus on the screen. > > MR. Bill Hi, EOS cameras measure "ordinary" exposure using sensors in the pentaprism area. The sensors in the bottom of the film chamber are either for AF (using a "secret" mirror hinged behind and below the main mirror, or are for the TTL flash system. E-TTL cameras measure flash exposure using the same sensors as used for "ordinary" exposure, but at a different time - they use the pre-flash which is transmitted just before the main flash, or if mirror-up delayed action is selected, they measure just after the pre-flash which is transmitted just before the mirror goes up - so that the returns can be measured by the sensors in the pentaprism housing. Malcolm Milton Keynes, UK www.megalith.freeserve.co.uk/oddimage.htm http://myweb.tiscali.co.uk/ms1938/ * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
