ryan constantine wrote:
> 
> do these take into account brightness intensities or just colors?

Well, I haven't dig up most of the intensity data but here's an example:

One standard candle:             13 lumens
  60 watt incandescent lamp:  1 000 lumens
1500 watt incandescent lamp: 34 000 lumens

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.


______________________________________________________________________
Kari Kivisalo                                  http://www.kivisalo.net

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