Originally posted by c.perkins
Are their any things to consider in metering with a brighter focus screen ?
Or will the camera just do it's thing like it always does ?
Clarence
I have both the 645 and the 645N. I suspect the 645 viewfinder may be darker on your camera due to the fresnel screen. I have the original split center focusing screen and it is marginally darker than the 645N.
The metering will not be affected by the focusing screen. A brighter screen will just help you manually focus. The biggest factor is the lens. With my 75mm f/2.8 prime, the screen is considerably brighter than, for example, with a 55-110mm f/5.6 zoom.
Correction: I'm not 100% sure, but I believe I was incorrect in my earlier statement. So if we're comparing the OEM 645 screen and finder vs. the OEM 645N screen and finder, the brightness difference is not an issue.
However, the light meter sensor on the 645 is probably up in the pentaprism and would be affected by a brighter focusing screen if, for example, you went from an OEM screen to a non-OEM Beattie screen. In this case, I would use an external light meter to compare the readings off an 18% grey card on the 645 vs. the light meter reading and if there is a difference, set an exposure compensation. The last thing you want is to underexpose your negs if the brighter screen fools the meter into thinking there is more light than there actually is.