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(meteorobs) Visual magnitude
The question of how visual limiting magnitude (the 6.0, 6.5, 7.0, etc everyone
constantly refers to) relates to "true" sky brightness (mag/arcsec^2) is one
I've wondered about myself - and has implications far beyond astrophotography.
There's no question different people will report very different limiting
magnitudes on the same night at the same location: differences in vision,
low-light response, color response, and even visual training are the reason.
However, I'd suggest that "true sky brightness" would ALSO be dependent on the
sampling mechanism (i.e., on the individual if it were measured by eye)! In the
end, the only comparison which has any meaning is between two detectors with the
same characteristics: two film plates with the same reciprocity failure, two
pairs of eyes with the same response, two CCDs with the same power
characteristics, etc. Corrections to this thinking are welcome, by the way!!
That being said, though, *IS* there a simple function which can relate an
individual's limiting visual magnitude to the true sky brightness?
Lew
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