I was measuring the PAR light coming from a white ~170° 1W LumiLED LED I got from a broken emergency sign,(the LED's are fine)
and the difference in intensity from the focused light coming from one of the LED's in a 3x1W E27 spot was surprisingly huge.
The 170° LED was losing it's power at a phenomenal rate when increasing the distance to the PAR meter,
it's was on the order of 1" - 700uMol - 2" - 300uMol - 3" - 75uMol.
I have not found out yet how much the light is loosing it's intensity when traveling through the atmosphere,
or gets degraded. I'm thinking about all the water molecules and dust particles that's in the air, maybe absorbing and/or degrading the light.
Looking at my MicroVeg, it's clear that the light composition is not perfect, the plant grows fast alright but is kind of thin(It was damage during sprouting thou),
vs the ones I got under the LED grow light or CLF, but the intensity in PAR is equal to that of sunlight, and note how the rest of the room is dark, light is only where it's needed.
In one of James Burke's Connections series hi says:
"Every new inversion looks like what it replaces, to gain quick acceptance.
The first car looked like a carriage the first printing looked like handwriting.."
I thought boy is that the case with LED grow light and the LED/CFL lighting industry in general.
A good example of the old way:
And the new perhaps: the module was using 3-5W after 2 days the plant had doublet in size.
A great portion of the light is directed directly at the plant and nothing else.