Simple Enough Control, But Fades In/Out

Im surprised Mac doesnt have this out of the box; seems like it should. Its very simple to use. I only have one problem: the setting I choose doesnt remain constant, it fades darker and lighter, like its trying to do a light adjustment. Its not always doing that consistently. It would be nice if it was consistently at the brightness setting I chose. Reminds me of the screen brightness adjustment feature my Nexus 7 has.

bmnetdevguy about Brightness Slider