On 03/07/2018 00:19, Andy Burns wrote:
GB wrote:

Lumens are defined as the light per unit of solid angle. So, focusing
the same amount of light into a tight beam does indeed increase the
lumens. Still...

I thought Lumens was Lumens (probably should be lowercase) and if you
wanted to include the angle they were spread over, it was something like
lumens per steradian?

I think that's the definition of a candela.

--
Max Demian