"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." If you’re shopping for a flashlight, you may think looking at how many lumens it puts out is the best way ...

One of the most common specs used to compare projectors is a measure of how bright each model is: lumens. This is because, in theory, a 1,000-lumen projector will be brighter than a 500-lumen ...