Lumens measure the brightness of projectors. Projectors come with an assigned level of lumens, with the brightest, or highest lumen, projectors being the most expensive. As projector bulbs age, their brightness can decrease as much as 80 percent – before the bulbs burn out. While increasing the lumens of a projector beyond its rated brightness is not possible, you can reduce the number of lumens lost by bulb age. Warnings Writer Bio
