Courtesy of Rhett Allain
But what about the colors of the video projector? It does essentially the same thing. However, instead of small RGB lights, it projects RGB colors to different locations on the screen.
black projection
Now we are ready for the fun stuff. How do video projectors emit blacklight? There won’t be a black light any Light, as we have seen before. How do you not project anything? First, let’s think about a screen like a TV. If you have three small lights (red, green, blue), you can create a small black dot by turning off all three colored lights at that point. Boom, it’s black!
So is it possible to just turn off the projector and make it black? That can’t be possible, right? If so, you won’t be able to tell the difference between the projected black and the screen even without turning on the projector. Yes, that’s exactly how it works.
Check it out: In the following image, I am projecting a slide that is half black and half white. The slide takes up most of the screen.
