Being a photographer, I have a professional light meter which also measures light in luxes. How should I multiply or divide the quantity of lux units in order to get lumens.
1 lx = 1 lm/m2
But no datasheet of LEDs shows lumens per square meter, there are just lumens.
I have found this conversion but I also get weird results, no matter what I convert to.
For example, my room is lit by a 23W Philips bulb (tungsten). The meter shows 12lx from a 1m distance. When I try to convert it, I get:
My room is quite big and I don't believe that a 12lm/m2 LED will replace my 23W bulb (equivalent to a 100W filament bulb).
So what's the deal with this conversion? I would like to perform some experiments but I simply don't know what are these lumens without any suffix. All the lumens I get are 'per square something'