Since nobody bit...
I spent a couple hours this evening testing meters and lenses.
Items tested: Polaris handheld meter with incident dome, E-1 in
spot, ESP and average modes, Minolta A1 in all three modes,
14-54 zoom, 100/2.8, 24/2.8 and 35/shift. The E-1 with 14-54
zoom was tested shooting both ambient and flash.
Thom's analysis of how the histogram is supposed to show a
midtone was rather enlightening. I used that information to more
correctly interpret the histogram display.
1. The 18% Kodak Graycard does measure 1/2 stop darker than the
incident meter reading. When properly exposed the graycard,
grayscale and color patches are exactly as they are supposed to
be. If I measure the graycard with the camera's meter,
Everything is 1/2 stop too light. This is as it should be.
2. When using the E-1's ESP or Average metering mode, the
histogram hump appears just to the left of center. (just like
Thom says it should). This is a full-frame view of the graycard
and having the viewfinder shade engaged. The E-1's spot metering
mode resulted in a 1/2 stop overexposure and the centering of
the histogram hump. The ESP and Average metering modes were
100% in agreement with the incident meter.
3. The incident meter nailed the exposure exactly. It gives me
1/10 stop accuracy and the E-1 is adjustable in 1/2 or 1/3 stop
intervals. I actually can us the meter exactly as specified.
The meter's documentation about being 18% is obviously bogus. :)
4. I tested all lenses at F5.6. The 24/2.8, 100/2.8 and 14-54
zoom gave identical readings. However, the 35/shift measured 1/3
stop off. It looks like the 35/shift has a slightly reduced
transmittion factor as compared to the other lenses.
5. The spot meter reading was 2-stops off. I haven't been able
to use the spot meter with the analog zuikos and will have to
figure out a way to do so.
6. The 35/shift lens had a 2-stop variance in meter readings
from dead-center to maximum shift. This is due to the mirror
size and vignetting in the light path. It's important to meter
the scene with the lens centered. This, of course, is true with
any shift lens on any camera.
7. The 35/shift lens has a slight light fall-off when the lens
is fully shifted, but is easily corrected in PP. Total variance
is between 1/3 and 1/2 a stop depending on aperture selected.
8. I'm not going to get into A1's metering.
AG
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