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.
Don > -----Original Message----- > From: Godfrey DiGiorgi [mailto:[EMAIL PROTECTED] > Sent: Thursday, January 05, 2006 12:26 PM > To: [email protected] > Subject: Re: MicroPrism ist-D Focus Screen is here! > > > Which meter pattern are you using? Matrix, Spot or CW Averaging? > > Godfrey > > On Jan 5, 2006, at 1:46 AM, Don Sanderson wrote: > > > 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. > > I haven't compared the results with the new/original screens > > using TTL/PTTL flash yet. > > I assume it would have no effect on TTL but may on PTTL. > > In PTTL the preflash is before the mirror goes up and the > > main flash is after. This is evident from the fact that you > > can see the preflash thru the viewfinder. > > > > BTW: Having this screen makes it _very_ obvious just how > > inaccurate AF can be sometimes. Makes the DA lenses focus > > clutch seem even more valuable for "touch-ups". > > > > Don > > > > > >> -----Original Message----- > >> From: Shel Belinkoff [mailto:[EMAIL PROTECTED] > >> Sent: Thursday, January 05, 2006 2:39 AM > >> To: [email protected] > >> Subject: RE: MicroPrism ist-D Focus Screen is here! > >> > >> > >> 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 focus looks pretty good on the pics you posted .... > >> > >> Shel > >> > >> > >> > >>> [Original Message] > >>> From: Don Sanderson > >> > >>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7573618765 > >>> > >>> Here are the focus accuracy results using the microprism center: > >>> > >>> http://www.donsauction.com/pdml/istD_FocusScreen.htm > >>> > >>> This is with a Sigma 50/2.8 macro wide open, focus point was the > >>> highlight in the top birdies eyeball, manual focus. > >>> Seems absolutely spot on to me, though the screen seems a bit > >>> less bright than the original, focusing was very easy, the > >>> microprism effect was quite pronounced. > >>> > >>> Autofocus seems to not be affected in any way. > >>> > >>> The new screen seems to increase exposure by about 1/2 stop. > >>> > >>> All in all, a good $30.00 spent for a focus challenged person > >>> such as myself. ;-) > >>> > >>> One Caution: The new screen is a bit thicker so it loads the > >>> springs on the closed retainer frame a bit more. > >>> When you release it, be ready to catch it as it pops out! > >> > >> > > >
