[net.rec.photo] f stops and foodcandles

reh1366@hou2b.UUCP (R.HOWARD) (05/10/85)

I once saw a table claiming to convert exposure readings on a 
camera to ambient footcandles.  It involved setting the ASA to
100 and fixing the shutter speed.  The f stop at the proper exposure
was directly related to foodcandles.  The table was weird in that it
didn't scale in any reasonable way with f-stop (ie, sqrt, power law, etc.)
Anybody know the real conversion?
Thanks.
Rich Howard
hou2b!reh1366