How does a film projector display black?

Courtesy of Rhett Allain

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

Projection of Black Color

Now we’re ready for the fun stuff. How does a video projector remove black light? There would be no black light any light, as we have seen before. How do you not project anything? First, consider a screen such as a television. If you have three small lights (red, green, blue), you can create a small black dot by turning off the lights for all three colors at that point. Boom, it’s black!

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

Check this out: In the image below, I’m projecting a slide that’s half black and half white. The slide takes up most of the screen.