Teacher, I use this class in terms which would be a priori far from optimal: the curtains let in light, the number of students is high, etc. I bought this product for its reasonable price and ease of use (unlike others, this projector has an internal memory, so it is possible to use it without having to connect it to anything). So okay, its brightness is slightly less powerful than that of fixed projectors, okay you have to convert its files, okay must connect portable speakers when one wants to obtain a slightly higher volume, but Overall this is ample for the use that is made in class. My only regret: a tripod is not supplied with the unit.
