-=> Mike Ross said to Greg Mayman
 -=> about "VEHICLE LED'S" on 08-31-03  02:35.....

 MR> IIRC the Lumen is related to the Steradian which was used to describe
 MR> the area (a square foot?) illuminated on the surface of a sphere with
 MR> a given angle at a given distance (1 foot?) by a unit candle but I
 MR> think the Candela is relatively recent unit and is what is now
 MR> typically used to describe a LED's light intensity. It is a point
 MR> source type unit. I think that at a standard angle and intensity there
 MR> is a unit relation that can be made between the Lumen and the Candela,
 MR> if I'm not totally out to lunch. I dimly recall writing in my notes
 MR> something about it. Now where are those notes...!

You're making me dredge up stuff from 50 years ago. Yeah, I
remember the steradian... isn't it one two-pi-th of a sphere? 

I'll have a think about it, but I _am_ getting older and slower
these days. I'll let you know if and when I find a solution ;-)

From Greg Mayman, in beautiful Adelaide, South Australia
   "Queen City of The South"    34:55 S  138:36 E

... I'd love to, but there's a disturbance in the Force.
___ Blue Wave/386 v2.30

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