Does the size of an emitter matter?

Let me explain myself. I never can think of a way to word titles. Imagine a scene with a plane that is 10x10 blender units and a cube above it that is 1x1 blender units. The cube has an emission material set to a strength of 1 and the plane material doesn’t matter. Ok will the cube light the scene more if both the cube and the plane are scaled up 10x?

You see what I’m asking now? Does relative size matter? Small emission objects don’t give off hardly any light and in order to make them emit more light you have to change the strength and that changes the color. I wish there was a way to stop it from changing the color. I know its probably more realistic, but it can be a pain in the ass when you want less realistic but more freakin light. =)

A larger emitter will give off more light, the scene will be brighter, but the shadows will be more diffuse and soft. In your example, the plane will expand on the x and y axes, but the cube will also expand on the z axis, meaning the emitter will not only be larger, but will be five units closer to the plane. You can adjust the color of the emitter’s light to get it the way you want it.