The center of every child’s education is rightly the teacher, but more often than not the center of attention in the classroom is the projector. It not only makes sure that the whole class can see the lesson, but can grab the attention of students in ways that a chalkboard can’t.
To see what the state of the art for classroom projectors is, we gathered together five different devices and ran them through the ringer at Administr@tor’s TechLAB facility. All had to be able to project at least XGA (1,024 by 788) resolution and sell for $650 or less. Other than that, anything goes.
The breakdown of the five projectors we got reflects the general market with four of them using TI’s Digital Light Processing chip (DLP) to create the image. It might sound like magic, but DLP technology involves hundreds of thousands of tiny mirrors each of which can be pivoted into and out of the projector’s light beam. This selectively reflects individual pixels to create the image. Add in a spinning color wheel and you have a colorful image on screen.
Projectors from Acer, Dell, Optoma and Viewsonic use this technology, but the loner of the group was Epson’s PowerLite X15. Rather than a DLP chip, it’s old school all the way with three tiny LCD screens. This projector divides the light into red, blue and green beams and sends each through a separate display panel. Near the lens, the beams are combined to create the projected image.
Each of the projection technologies has its pros and cons, but it often gets obscured in marketing mumbo-jumbo. The key differences are that LCD projectors require an air filter, which might prove to be a hassle to periodically clean or change, but can produce brighter and livelier images, while DLP projectors can be made smaller and lighter.
At TechLAB, our job is to separate the winners from the also-rans. In addition to examining each, trying out their features and measuring their brightness, we looked at how long they take to start-up and shut-down as well as how noisy and how hot they were in typical classroom situations. We used several different types of systems with each, including a couple of tablets.
Finally, by mimicking what you do in class, we finished off with a three-tier simulated classroom lesson that stretched each projector’s abilities by using a series of online interactive elements. It was very instructive, to say the least.
Whether the projector lives on a cart that is wheeled around, carried between classes or permanently mounted in a classroom, all five have one thing in common: an expensive and power-hungry high-pressure lamp that creates an intense beam of light. The cost of replacement lamps and electricity can end up costing more than the projector itself after a few short years of use.
That’s why we not only measured how much power each projector uses – both when it’s on and when it’s off – but include how much its replacement lamps adds to the total. Together, they form an estimate of the operating expenses of each projector if it is used for 8 hours a day over the typical school year.
The use of expensive high pressure lamps is the mainstay of the projector industry, but that may change soon. As LEDs get brighter and brighter, they could replace traditional lamps and offer two big bonuses. They have a rated lifetime of roughly 20,000 hours – 12 years of typical school use – so replacing projector lamps can be a thing of the past. Plus, they use a fraction of the electricity that the traditional lamp consumes, so they have much lower power bills.
In the meantime, any of these classroom projectors can reliably put a quality lesson on the classroom’s big screen, but one goes to the head of the class. Epson’s PowerLite X15 not only created the sharpest image with the best color balance but was the most flexible for setting up in oddly shaped rooms. Its only major failing was the lack of networking, a problem that’s shared with several others here.
It may not be the least expensive or the brightest, but the PowerLite X15 is the current best buy in classroom projectors and can teach its competitors a thing or two about how to succeed in the classroom.