Do heat cycles degrade bulbs faster than letting it run, or vice versa?
Like if I'm going to watch a game in the afternoon, and then a movie a few hours later.... Am I better to leave the projector on, or turn it off and back on again a few hours later?
Turn it off, at least in terms of bulb life. The most common number of minutes thrown out there as the threshold for when it behooves you to turn it off is 20 minutes, and I think even BMX has said the same thing. IOW, "one strike" = "about 20 minutes taken off bulb life".
For me, however, I usually just leave it on if I'm back in 20 minutes. Even longer, perhaps 40 minutes, up to an hour. Few hours, I definitely turn it off.
I just like to baby the PJ away from unnecessary strikes.
I'm sure it's all good.
EDIT: Oh. I know it's been answered already, but,
NO . . . there isn't anything that BMX doesn't know about projectors.