We recently bought a unit for our department, to replace the overhead and slide projectors that had been mainstays at our morning rounds for years. Now, residents and staff can create and update their presentations with the latest laboratory and clinical findings minutes before rounds begin. And visiting lecturers are relieved to learn that they can leave their electronic projector at home and travel with only the laptop computer containing their presentation. A typical brightness rating for an electronic projector is about 450 to 500 lumens, but some units go up to 1,200 lumens. With a higher brightness rating, you'll be able to leave the room lights on while you give your presentation.
Lower contrast produces muddy images.
Most good-quality units can produce images with a diagonal measure of 2 to 25 feet. Better optics and a higher brightness rating allow for larger images, but a 25-foot image is usually sufficient. Don't compromise on this variable. Don't be fooled by interpolated- or compressedresolution figures. Lamp life varies from a few hundred hours to several thousand hours.