Godfrey, could you tell us where you found this info? We were discussing it the other day, it would be nice to have a reference source. I know the older meters pretty well but the technology has passed me up. ;-)
Thanks! Don > -----Original Message----- > From: Godfrey DiGiorgi [mailto:[EMAIL PROTECTED] > Sent: Thursday, January 05, 2006 5:30 PM > To: [email protected] > Subject: Re: MicroPrism ist-D Focus Screen is here! > > > The Spot pattern sensor reads off the focusing screen and is not > exactly aligned with the optical center of the viewfinder optical > system, thus the metering discrepancy. > > CW Averaging and Matrix meter patterns are read from sensors in the > bottom of the mirror box and should cause no discrepancy in meter > readings at all. I believe that the P-TTL/TTL flash sensors are co- > located with the CW Averaging and Matrix metering sensors. > > (Far as I'm aware, this is correct information for D, DS, DS2 and DL > bodies.) > > Godfrey > > On Jan 5, 2006, at 2:17 PM, Don Sanderson wrote: > > > I tested with the spot pattern. > > I'll try again with the others but the 1/2 stop really isn't > > something I'm too worried about. > > > >> Which meter pattern are you using? Matrix, Spot or CW Averaging? > >> > >>> The new screen requires you to use -0.5 exposure compensation > >>> to get the same meter readings as the original screen. > >>> IOW the camera thinks the scene is 1/2 stop darker than it is > >>> and will overexpose without compensation. > >>> This would indicate the meter is behind the prism as others > >>> thought and not behind the mirror as I thought. > >>> > >>>> Could you elaborate on that a bit? How does it increase > >>>> exposure? Does it > >>>> require a greater exposure time for the same results as the > >>>> original > >>>> screen, or less? > >>>>> > >>>>> The new screen seems to increase exposure by about 1/2 stop. >
