I am modeling (in Ecotect v5.6) a light pipe in a very simplistic manor, just as simple light with a profile of 1.0 for angles 0 to 50deg and 0.0 for all others (60deg to 180).

The radius is 10" and a spec defines the luminous flux at 15000.

So I calculated the luminous intensity as 5681 candela, and plugged all the numbers into Ecotect:

5681 cd

15000 total lumens

10" radius

and defined the profile (candela polar plot) as 1.0 (0 to 50deg) 0.0 (60 to 180deg)

Problem #1

The first problem is that Ecotect does not seem to produce the same RGB radiance values as the 'lampcolor' program. When I export from Ecotect to Radiance with the above values the Radiance 'light' object has RGB values of 1416.6, but lampcolor produces 131.6 (for a ring of .254m radius (10") and 15000 lm).

So I have to 'fake' out Radiance by entering a much lower value for total lumens in Ecotect so it will generate the correct (131.6 RGB values), a value of 1400 lumens in Ecotect gets close (132 RGB value).

There is the first question, why do I have to use 1400 lumens when it should be 15000?

Problem #2

Then, the second problem, even using 1400 lm I still get lux values in Radiance which are about 3 times greater than the electric light simulations in Ecotect!

So, what am I doing wrong?

thank you in advanced for any feedback.