On Wed, 24 Dec 2014 17:38:37 +0000, Tim Streater wrote:

This overspill is presumably unwanted light directly from the lights.

That is how I would read it as well.

What about light reflected from other objects.

That would be additional and dependant on those objects, light
coloured or dark?

As for what 1 lux is, the ambient light in this room is 40 to 50 lux
according to the light sensor in my tablet with it "looking" at the
white ceiling. The small galley kitchen with white walls/ceiling lit
with a bare 5' 58 W flourecent is 150 ish lux when shaded from the
lamp. Phone doesn't have a light sensor so can't collaborate the
tablets reading.

--
Cheers
Dave.