Primary Colors of Light - Mixing of Colors

When the primary colors of light, red, green, and blue are mixed, white light is produced. By looking at the shadows cast when an object blocks one or more of these color components, one can observe both the additive and subtractive processes of color mixing. Instead of subtracting light via an absorbing pigment, the object's shadow "removes" the component color from the "white" light. For example, the yellow shadow is the result of blocking the blue led and only allowing red and green to mix. Similarly, yellow pigment absorbs blue light and reflects red and green. The addition of red and green light makes yellow. The bluish-green shadow - CYAN - is the result of blocking the red light.
Where the cyan and yellow shadow overlaps appears to be green. Why? This small shadow is where both red and blue are blocked. Likewise, when we mix cyan and yellow pigment cyan absorbs red and yellow absorbs blue. The only thing left to be reflected is green. Cyan pigment and yellow pigment both reflect green, so that's what we see. (In white light)

This is the bulb I used.
It is good at either red, green or blue,but when you try a mixed color with a single bulb the results are disappointing. They let you mix the led output to create other colors but the light doesn't blend well. You get bright spots of red or green or blue with a blended color between the spots. would be better with some kind of diffuser.

[craigtovey]

The eye's color receptors are more complex than simple blue, green, and red detectors.  Instead, each of the three kinds of receptors has a unimodal response function, shaped somewhat like a bell curve.  One of those functions peaks somewhere in the blue range. The other two peak at longer wavelengths.  When light with a violet wavelength (shorter than blue)  hits your eye, your brain takes the information that blue by far has the strongest response, but also that the responses of the other two are less than they would be if the light were blue (because violet is farther away from their peaks than blue is).  Your brain then infers that the wavelength is even shorter than blue. 
    Color perception is even more complex than that, however.  Humans are biased towards blue because one of our receptors peaks there.  To most animals, the sky does not appear blue!  If we had an indigo or violet peaked receptor, the sky would look indigo or violet to us.

[lynnfallible]

I'm an online tutor and this is the closest I could get to explain white light and dispersion. I know this is not the purpose of your video, but it would be nice if you made a demo to make white light. It's pretty hard to find a good quality video. Thanks though!

[lidonevitas]

Lo que siempre te enseñan en clase de imagen, pero que nunca llegas a comprender porque o no lo saben explicar bien o porque no saben que existen vídeos como este que lo demuestra ¡estupendamente!

[bockphysics]

no they're not. That's the point of the video. primary pigments are cyan, magenta and yellow. Mixing them is a subtractive process where each pigment subtracts one of the primary colors from white light.Yellow pigment appears yellow because it absorbs blue light and reflects red and green light. Red and green light mix to make yellow.

[MrShadowthrone]

Is that orange behind the ball from blue and green making yellow and then the red making it orange? Or is there something else? Blue sky turned orange during some kind of heat stroke for me many years ago, has perplexed me to this day.

[bockphysics]

I don't understand this question. The rainbow is the entire spectrum of wavelengths of light visible to our eye. Our eyes detect regions of wavelengths that correspond to blue, green and red. The other colors are produced in our brain as a mixture of stimuli of these blue, red, and green receptors.

[ayshatunowfa]

There is an red green and blue mix it together when it is white?

[bockphysics]

No. Objects appear the color they do because of the wavelengths of light they reflect that then enter our eye. If a ball appears green in "normal" white light it is because it reflects green light to our eye and absorbs the other major regions of colors to which our eyes are sensitive. Red and blue light is absorbed, therefore if I shine only red light on the ball then it will be absorbed and the ball will appear to be black and colorless.

[munawarshah]

What will be the color for Yellow light and green light
please tell

[zebop]

And what about non-primary ones? Suppose we mix blue and yellow lights. Yellow itself is a mix of green and red, so all three types of receptors would be stimulated and the resulting color would be what, white? I expected to get white, but I guess the color filters I used were not very accurate because I got something I'd call bluish grey.

[JfhuTheJedi]

thank you i am currently learning about colored lights in my Computer information science class and i wanted to see this actually done then just picture drawings explaining it.

[alyssasmith]

what are these flashlights called? what website did u get them from?


(answer and i’ll sub)

[bockphysics]

If we had a room bathed in red light, then everything in that room will either reflect red light and appear red or absorb red light and appear black. If we have only red light illuminating the room then that is all that can enter our vision.

[luisardilaful]

disculpa lo que esta ahi blanquito q es?? puede ser cualquier bolita blanca?

[bockphysics]

In the description I've added a link to the type of bulb I used.

[jbmgil]

Hi! Can I achieve the same result using celofane in front of the light surces?

[copperredheadht]

I'm familiar with understanding the color pigments:cyan, magenta, yellow and light colors are red, blue, green. If we have a white object and hit it with a green light the object would appear green and shadow would be the complimentary color magenta and dark. But is there a formula or pattern for understanding what the shadow color will be if we use an object of any color like a yellow object and hit it with a green light what will appear? My find is the objects is lighter green & the shadow is red.

[raeesaummar]

in the rainbow which colourcan be formed without the primarycolours

[rubiconzj]

so if i had a green ball and i wanted to make it yellow i would shine red light on it?

[beanford]

Hi, I am attempting to repeat your light demonstration and I was wondering what type of lightbulb you used? Were they pre-colored lights or did you add the filters? Were they incandescent, LED, halogen??? If they were factory made colored lights where did you purchase them? Any information would be helpful as I am not having quite the success you did. :) Beanan