Wanted a 'portable projector' and this was the top of the class from my research. However, that is probably its worse quality. Maybe because it isn't plugged in I notice the big brightness drop and after 2 hours is getting to the end of the battery. But once it is plugged in I enjoy all the perks, brightness increases that I can easily watch it with lights on (same with unplugged but to a lesser degree), and it is portable, like a laptop WITH PLUG AND PLAY, that I can move it around the house and project on flat bare walls. Not sure about projecting on roofs in its user manual, but lying down and projecting 90 degrees with a 'makeshift setup...view more