On Wednesday, May 11, 2011 7:34:16 AM UTC-7, dadiOH wrote:
> Procedure
>
> 1. Add up the total potential lumens from all bulbs
>
> 2. Divide the total by the area of your shop. You now have the maximum
> light AT ONE FOOT FROM THE BULBS
>
> 3. Apply the inverse square law to determine light at work surface height.
> a. at two feet from bulb, light will be 1/2...at 4', 1/4...etc.
That's overly pessimistic; firstly, the square law doesn't apply to
four-foot-long fixtures until you're over four feet away. Second, the
light will reflect from walls and floor and such, it isn't escaping into
an infinite void.
End-to-end fixtures (basically a long line of light) is best scaled
by an inverse-R law, not by an inverse-R-squared law.