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http://www.candlepowerforums.com/vb/showthread.php?t=174000
There is no direct conversion. They are physically different concepts.
Foot-candles are a measurement of light intensity - how "bright" is the illumination striking a particular object or surface. It is a measurement that is taken at a single point. If you have a large surface, you need to take a whole bunch of individual foot-candle measurements at different points in order to get an overall average. It is common to find foot-candle recommendations in the field of ergonomics and industrial engineering, where people need to be provided with adequate light to perform certain tasks. Foot-candle measurements obey the inverse-square law: if you double the distance from the light source, you will find the intensity is now 1/4 as bright.
Lumens are a measure of total light output from a source. If you could take a foot-candle measurement at every single point in the entire beam pattern of a particular source, and multiply by the total area of the beam, you would end up with lumens. Distance from the source makes absolutely no difference.
Hope that helps. You mention you are trying to light a workspace - care to describe the situation in greater detail?
__________________
Steve Offiler
Central Tools, Inc.
www.centraled.net
"mherrcat"
I've satisfied myself with the comparitive self test, 10w incadescent vs MarineBeam vs Sensibulb 2
For both general area lighting/ Cabin overhead fixtures and our area reading lites the Sensibulb gave the brighter (brightest according to Practical Sailor Jan '09) output.
My 80's era fixtures with the "diamond tread" glass diffuser lens appears to compliment the Bulb? output.