Lumens to Kelvin

[StirCrazy]

Originally Posted by danny zubot

Steve, Can you provide a thread for us to read about this. Apparently I had some misconceptions as well.

I'll see what I can dig up.. shouldn't be to hard to find them out.

OK I screwed Lumen and LUX up again

a Lux is lumen/meter^2

a lumen is the direct measurement of light power, or
"A unit of light flow or luminous flux. The lumen rating of a lamp is a measure of the total light output of the lamp. The most common measurement of light output"

for further info the Lumen is a rating for for which the standard is light of 555 nm wave length only.

So in simple terms, a lumen is a instantaneous reading of the intensity of light at a 555 nm wave length.

as for Kelvin, it is a direct relationship between the temperature of a black body object (a lot of metals behave like a true black body) and the color it emits due to its temperature. like when you heat up a chunk of metal with a torch, it goes through color changes that correspond with the temperature it is at and the temperature is measured in Kelvin not Celsius or Fahrenheit.

here is a page to play with to see how it works.
http://cat.sckans.edu/physics/black_body.htm

Steve