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Light Meters
<< Photographic ligth meters trade range for resolution. They are capable of
measuring very brigth and very dim ligth, but cannot tell the difference
between ligth levels that are too close apart. A difference of a 1/4 f/stop
corresponds to a factor about 20%, and its' hard to get from a regular
photographic meter. I believe meters designed specifically for aquarium
use would work on a narrower range of illumination, but would provide better
resolution. >>
Yes Ivo and they are called One Degree digital spotmeters. I've been using
one for years with my large format work and for double checking the
calibration of the metering of my F4 and other systems. Not cheap these
days. A decent one will cost anywhere from $200.00 on up. ANd a good one
will meter such a small increment as you cited but B & W film latitude is
rather forgiving. Color Transparency film is not. Define what you mean by
resolution please. In traditional terms, resolution is defined by resolving
lines or whatever per X. Then there's actutance. As far as defining a one
point difference, a good digital spot meter will do that easily. remember we
can be talking about one inch at 100 yards. If you can hold the meter
sufficiently steady you can read the shadow values, or highlight values and
adjust your expose so that the desired reading falls where you want it on the
curve of the film.
David
David