If you keep in mind that light falls off by the
square of the distance, you will start on the right "track" for
proper placement of your fixtures and for choosing the right wattage and beam
angle (if applicable) for your bulbs.
What does this mean? Moving a fixture with a 50W MR16 (12V) to a location twice the
former distance will result in a light level of NOT one-half the previous
light level, but ONE-FOURTH the previous light level. By the same token, moving the light source to one-half the
distance will result in the light level not doubling, but quadrupling, being
about FOUR times the previous light level.
How can this be applied? If you want to use the track itself as a design element by
suspending the track on pendants and you have already determined that 50W MR16
lamps would be perfect at the ceiling height, you could calculate the new
distance from the light source to your reference point and perhaps employ 35W
or even 20W MR16 bulbs. Likewise, using stem extensions to suspend
fixtures from the track to the desired height will often
allow reduction in lamp wattage.
So what? Consider this: If a
light burns 8 hours per day, 5 days per week, every watt of that bulb
costs about $0.21 per year in electricity (based on a kilowatt hour
@$0.10). If you can get the light level you want and reduce wattage by
30W, you have virtually pocketed $6.30 PER YEAR; and, if you can buy
electricity at a mere $0.10/kwh, congratulations!
At least in one sense, it's like getting free
light bulbs. Check
it out.
