We are missing a piece of data. I think we have to account for area the light is shining over. Here's why.
IF, the EVL has 8900 lumens at 12", then:
Given E=I/D**2, with E=8900 and d=12", I=1281600
However, looking at the link from regularguy, it talks about the area over which the light shines. So the I number above could be total engery output, which would have to be divided over area.
If I use I=1281600, I get an E of 205056 lumens, which is an order of magnitude off. However, if that is truly energy out and you divide it over a 10" area, it comes out. But I think this is suspect.
Seems to me we are missing something or applying the equation wrongly, but close.
Let me look into this alittle more too. Now where's my Physics book????????????
Thanks.
Choader |