<<<It never fails, just when I'm getting comfortable with what I know about the
mechanics of photography, I learn that I shouldn't be. This seems to remind
me that the 'f-stop' or wide open aperture rating of the lens is just a
ratio of two measures, but I can't recall the specifics. focal
length/smallest passage width of light? Even if it only slightly resembles
the truth, it explains why the f8 mirror is darker than a glass lens stopped
to f8. Hmmm... and yet the metering still works ok. How can that be? Now
I'm truly muddled.
-Mickey>>>
The meter measures whatever hits the silicon cells. If a cloud crosses the sun,
if there is only candlelight, or whatever the light conditions are, it will
measure it. To the Olympus all lens are at full aperture, unless told
otherwise. Mirror lens are measured at full aperture because this is what the
position of the aperture lever at the rear of the lens tells the camera. Lens
with aperture control tell the camera, 1. I'm wide open, 2. I'm stopped down
one stop, 3. I'm stopped down 2 stops, etc., etc. For 2 & 3, the shutter speed
has to lenghthen by 2x or 4x. In the Olympus system the actual aperture is not
communicated to the meter, only the number of stops from full open is.
I hope that this is not too confusing.
Warren
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