And my TIVO. Never, never, never. ;)
It is sound to only direct light where you want it to be, if at all possible. Wasting energy needlessly is not conservative... If you are buying a 100 watt bulb, and 40% is leaking towards the sky where you don't need it, does it not make sense to get a better system, and use a less powerful bulb to do a better job? You don't have to eat tofu and wear birkenstocks to see this.