by Jens » Fri Jan 06, 2006 9:02 am
My favorite answer:
It depends!
The power consumed (ie: the wattage) and the output (candela) are not directly related.
A 100 watt incandescent bulb (like the one in your reading lamp) has a significantly different light output than does a 100 watt halogen (like the one in a track light system) bulb or a 100 watt xenon bulb (like the headlight on an Audi).
In addition, the light output is also dependent upon wether the light is focused (like a spot light) spread (like a flood light) or omnidirectional (like with your ordinary household lightbulb).
Finally, whether it is AC or DC, and the age of the bulb also change these figures.
The easiest way to answer your question is to get a light meter and measure it in your application. Next easiest way is to contact the manufacturer and let them answer your question. Note that the answer is usually measured in foot-candles or lumens per area at a given distance so the measurement is only accurate for a single instance in a given application.
Hope it explains why we can't exactly help.
Jens