"Kari Kivisalo" <kar### [at] kivisalonet> wrote in message
news:39C480E0.D52CBAEC@kivisalo.net...
| ryan constantine wrote:
| >
| > do these take into account brightness intensities or just colors?
|
| So a 60w light is 80 times brighter than one candle.
|
| Light `flow' from a lamp is measured in lumens. A uniform point source
| of one candela (luminous intensity in any direction [defined for 555 nm
| radiant intensity of 1/683 watt per steradian] ~ one dinner candle) at the
| center of sphere of 1 foot radius gives 1 lumen per square foot. This is
| also one lumen per steradian. Area of the one foot sphere is 12.57 sq. ft.
| so the 1 cd. source produces 12.57 lumens.

Now can you do the change according to eye pupil size?  Just kidding.

Nice list Darcy, I notice I need to change my thinking about sunlight color
if I follow along with this since I almost always use red larger than green,
green larger than blue instead of a bluer sunlight.
The sky colors are read by me to be quite light cyan, almost gray-blue.  I
haven't checked any of these yet.

Bob

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