When you first embark on your projector research, you’ll quickly discover comparing projectors is an apples to, not oranges, but watermelons game. How can the same machine that does essentially the same job, project an image or video onto a larger viewing area, be so vastly different?
While many bells and whistles can account for the pricing disparity, the ability to play video pulled from a TV tuner, throw images or projects from a smart device, interactivity with different points of connection allowing multiple students to work on the same media, etc.--- the first aspect you will want to pay attention to is resolution. Projectors usually come with a “fixed resolution” so regardless of what data, video or images are entering the projector, the quality of the output will be the same. If a high definition signal is entering a lower fixed resolution projector, it will actually need to shrink that info to fit its standard format. This can sometimes result in a clunkier image.
Here is a cheat sheet for comparing different resolution projectors (this covers not only the often HD and high-end education models, but all the way down to a handheld pico or home theatre-level projector):
XGA (1024 x 768 pixels)
WXGA (1280 x 800 pixels)
WUXGA (1920x1200pixels -- widescreen)
HD (1920 x 1080 pixels)
4K (4096 x 2160 pixels)
There is also an SVGA level, though many ed tech apps won’t work with less than an XGA resolution (which is preferred for a 4:3 Aspect Ratio). As the above numbers highlight, an HD projector has about double the resolution of an XGA, while the 4K amps it up to nearly four times the clarity and definition. Resolution is the term for how many pixels are displayed on your viewing surface. A high resolution will have more lines of pixels within the same space, offering an enhanced picture quality.
Why Be Picky about Pixels?
The term pixels is short for picture element. These red/green/blue combo color pixels are often referred to in relation to their horizontal and vertical dimensions. When you look at a measure of number of pixels wide by the number of pixels high that can be displayed, more pixels per unit of area produce a higher resolution. Aside from the pixel resolution issue, another element to consider is the color resolution. Each pixel is further able to offer a different number of colors (we are talking in the billions per pixel, so this goes far past ROYGIBV matters). Essentially, the higher the color resolution or number of colors per pixel, the more lifelike your image will look. (A high dynamic range and 10-bit color offer extremely smooth gradation for a more naturally blended image.) So though it will affect your bottom line, bigger is better when it comes to quality.
First Find Clarity on What Meets Your Needs
If the majority of your projecting needs are simple bars, graphs and power points, perhaps the lower resolution XGA will suffice. It certainly will be more budget friendly. However, if you plan to use the wealth of HD teaching materials available or need to project detailed or complex images, aiming higher would make sense.