How Projectors Project Black (Easy Explanation)

As you have learned from your science class in fifth grade, black isn’t actually a reflection of light but the absence of white. So, how do projectors project black onto a screen?

how projectors project black

Projectors do not need to repel light to project black onto a screen. The way projectors project black is by not projecting them at all. So technically, projectors do not project black.

Also read: Will a Projector Work on Grey or Black Walls?

Are you confused? In this article, let us discuss the irony of the projection of black and how we can make your projector’s blacks even blacker.

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How Projectors Project Black (Do They?)

As we have discussed before, for projectors to project back, they will need not project them at all. It means that the color black of each projector will vary significantly with different factors. 

Later, we will discuss how to create better blacks for your projector. For now, let us go in-depth and take a deep dive into how black, or the illusion of black, is created by your projector.

How do we see color?

Have you ever stopped to think about how our eyes absorb color and why some objects are red and some are blue? Well, it all starts with the science of white light.

White light is the result of the combination of all colors of the visible color spectrum.

Because of this property of white, we can assume that white light contains all colors (except for black, which is technically not a color but a hue).

When white light hits an object, it is either reflected or absorbed by that said object. The color is reflected and not absorbed in the color that we see.

When we see the red in an apple, we technically do not see the red in the apple but the red reflected by the apple.

The apple absorbs all the colors from the white light except for red, hence why the cones in the eye (three types of eye cones: blue, green, and red) assigned to detecting the red light send signals to your eye-brain that it sees red.

So basically, when we see the red apple, the red is not actually inside the apple but is the color that is not reflected by the apple (so technically, the apple is not red, but the apple does reflect the color red).

The projection of black

When you hear that blacks are the opposite of white, they are technically accurate! If white is the combination of all colors, black is the absence of all colors, and it happens when all light is absorbed, and none are reflected.

Since projectors are light-based, they cannot project a hue that represents the absence of light. That would not only be ironic but scientifically impossible also. It is why projectors opt not to project the color black to make things simpler.

Why the projector’s relationship with black is complicated

Since projectors don’t project black, the black you see on the projection heavily relies on many variables. Improving the contrast of your projector is something we will tackle later.

In this section of the article, however, we will tackle the variables that affect the color black color in projectors.

The human eyes are a complicated pair of flesh. They are not only very intricate, but together with the brain, they fill their physical limitations with the brain’s cognitive abilities (just like how smartphones have AI post-processing built-in on their cameras).

Our eyes see colors relative to the colors in proximity to them. It means that if a very dark color is put on a sea of white, it may seem even darker than it is. Take the image below as an example.

How Projectors Project Black (Easy Explanation) 1

Image credits: Public Domain, Christopher S. Baird

Notice the two spaces surrounding the dots on the image. Although one seems lighter and the other seems darker, both are the same hue.

Now you may ask how this applies to projectors specifically. If the projected image contains blacks surrounded by many lighters, vibrant colors, it may seem dark. However, if the projected image’s black images are next to relatively dark images, it may not seem dark.

The surface is essential.

Since blacks on a projector are not reflected, the blacks on projected images will vary significantly concerning their projected surface.

It means that if a projector projects at a highly light surface, the black may not be very black as expected. On the contrary, if the projector projects at something dark like a black-painted wall, the blacks will be extremely dark.

For reference, let us refer to the image below. Ideally, a projector would project perfect blacks like the image on the left.

However, in practice, most projector’s blacks will largely depend on how the projected surface looks and will look like the one projected on the right.

How Projectors Project Black (Easy Explanation) 2

Image credits: Public Domain, Christopher S. Baird

The mystery of black: how does a projector make black?

Sadly, a projector does not actually “make” the color black. Since there is no such thing as black-colored light, projecting black is impossible.

Some projectors mix colors to produce a brown-like color used to represent black. Although not wholly black, our eyes perceive it as black nonetheless.

And now you know why a cinema turns the lights off – so the white screen is black in the absence of light. It makes the black items on film truly more black.

Three Frequently Asked Questions About The Projection Of Black

Should I choose a black or white screen?

For better contrast (to display better blacks), you should opt for a black screen. For a brighter image, you should opt for a white screen.
If you are watching in a dark environment, you should consider using a black screen since visibility and brightness are not an issue in light-restricted areas.

Are there HDR projectors?

Yes, there are HDR projectors. However, for an optimal experience, you should still curate your room to be built projector-first (in other words, consider the use of a projector when designing a room at all times).

What should I do to get a better quality image with my projector?

Ensuring that your projector is HDR, has the right amount of brightness, and has the right amount of resolution is critical.
Additionally, projectors are heavily affected by outside influence, so you should make your viewing room as dark as possible. Using black screens and having high-quality HDR video is also essential.

Sources

  1. https://wtamu.edu/~cbaird/sq/2015/06/16/how-do-projectors-project-the-color-black/
  2. https://www.amnh.org/ology/features/stufftodo_einstein/see_color.php
  3. https://www.pantone.com/articles/color-fundamentals/how-do-we-see-color
  4. https://wtamu.edu/~cbaird/sq/2015/06/16/how-do-projectors-project-the-color-black/
  5. https://pointerclicker.com/how-do-projectors-project-black/