Linear lumen?

[knabsol]

Hi there folks...
I was just wondering last night if we humans experience lumen in a linear way? I mean, does a 100 lumen lightsource look twice as bright as a 50 lumen source?
Maybe it´s a stupid or obvious question but I dont know
Cheers!

 

[worldedit]

Four times lumens gives you 2 times visible brightness. Thats bad if you use a flashlight. But helps to see in bright daylight and dimm moonlight.