From the moment Gamma Corrction came in Pro, I only use ONE infinite light.
Rarely, but it is extremely rare, I add a (very low settings) spotlight .
Never-ever, more then 2 lights.

There is only one sun. (Iside BB's sfere this single infinite light sun at 80%)
There is only ONE main light source in a room.

But Yes, I do use ambient to make things glow.
Like a PC screen, or a TV, or a candle light, or a lightbulb.

And YES, I use BB's sfere in all my renders.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!