How does a film projector display the color black?

Courtesy of Rhett Allain

But what about the colors from a video projector? It essentially does the same thing. However, instead of a bunch of RGB lights, it projects RGB colors in different places on the screen.

Project the color Black

Now we’re ready for the fun stuff. How does a video projector shoot black light? Black light would be the absence of any light, as we saw before. How do you plan anything? First, let’s consider a screen like a TV. If you have three tiny lights (red, green, blue), you can make a small black dot just by turning off the lights for the three colors in that location. Boom, it’s black!

So, is it possible to just turn off the projector to make it black? It can’t be right, can it? If that were the case, you wouldn’t be able to tell the difference between a projected black color and the screen without the projector even turned on. Yes, that’s exactly how it works.

Check: In the following image, they project a slide that is half black and half white. The slide takes up most of the screen.