[vsnet-chat 4053] Re: Color terms in visual observing

[Brian Skiff <bas@lowell.edu>]

     The paper Michael cites relates specifically to visual observations
by Max Beyer, and considers whether he used direct or averted vision.
An argument ensured between these authors and Brad Schaefer about this
in a series of papers that pretty much ended up inconclusive.
     Berto:  remember that photographic observations can be done in other
than blue light.  The data mentioned in the 1937C paper relate to photos
taken on yellow-sensitive films.  Similarly, Takamizawa's data are always
reported as "photographic", but are actually fairly close to standard V
since he's using Tri-X with a with a pale filter.  They should be noted as
"photo-visual" (pv).
     Given that an increasing number of chart sequences show standard V
magnitudes, I wonder if anyone has tried matching their visusal system 
more closely to it by always making estimates with a light yellow filter,
something like a Wratten 8 or equivalent, which would cut off whatever
blue sensitivity the eye might have that's outside the V bandpass.  
One could presumably make tests to see whether this produced more consistent
results than not using such a filter.  

\Brian

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