Date: Wed, 19 Mar 1997 15:47:17 -0500 (EST) From: Perry Malouf <pmalouf@access.digex.net> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg993$foo@default> Subject: Re: Lights
Chris Teichreb wrote about measuring light:
> Isn't there a way to do this using a 35mm camera
> and calculating it with the built in light meter?
Perhaps, but I'm haven't encountered the specific
method.
> that explains why incandescents of
> low wattage seem brighter (or at least to my eyes!).
I believe that fluorescents have a higher power-to-light
conversion efficiency than do incandescents. So
a fluorescent of given wattage should appear brighter
than a normal incandescent of the same wattage.
But, the apparent brightness of a source also depends
on its equivalent temperature. "Equivalent temperature"
is a description of where in the visible spectrum the
source output is centered (its strongest color).
35 milliwatts of light power in the green will appear
much brighter than 35 milliwatts of light power in the
red, because your eye is more sensitive to green light.
> Hey, I just realized that with what you're saying, the
> light I described could be low output but high energy consumption!
Yes, precisely! That's why a light meter is so useful,
especially when comparing light sources of similar power
consumption.
Regards,
Perry Malouf
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