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### Course: Pixar in a Box>Unit 5

Lesson 1: Introduction to color

# Spectrum of light

Every light sources makes a different kind of rainbow, known as a spectrum. Learn how color is a property of light, and how different light sources create various color effects. Explore the spectrum of sunlight, candlelight, and other sources, and understand the role of color at Pixar.

## Want to join the conversation?

• At you see a graph of a candle spectrum. The y-axis being intensity and the x-axis being wavelength (nm). What is nm?
(12 votes)
• nm is nanometer
(11 votes)
• what do you think people 5th-1st grade would think about this video?
(8 votes)
• I’m in 5 th grade and I actually enjoyed it gave me a different view of color and I learned lot I hope this helps lol
(5 votes)
• At if white contains all visible colors why when i mix all colors from crayons i dont get white?
(7 votes)
• Crayon colors work differently from colors of light. While each color of light added causes a new color to be reflected, each new color of a crayon or paint will cause more colors to be absorbed. Mixing red and yellow paint will give you orange (the same goes for red and yellow light), but mix red and green paint? You get a muddy color. Mixing red and green light, on the other hand, produces yellow. Hope this helped!
(6 votes)
• what i dont understand may i have some help? #ihateschool
(7 votes)
• Try turning what you are learning into something that you like, if you struggle with math but like Minecraft, you might try "32 grass blocks + 32 grass blocks = a stack of grass blocks, or 64 grass"
(5 votes)
• Colour helps me make simply boring things a bit more bright and fun. :D
(8 votes)
• radio waves is weaker than gamma ray because gamma ray's wave is 1 picometer which is really small while radio wave's is about 1 meter.
(5 votes)
• Does anyone else think that the eggs are TINY at :46?
(4 votes)
• wow khan academy is really nice
(4 votes)
• How does color reach your eyes?
(3 votes)
• What's a "supercomputer version of Photoshop."?
(3 votes)

## Video transcript

- You may be surprised that there is such a thing as a color scientist, but at Pixar, color plays a role in almost every artistic decision that we make. While this lesson will focus on the science of color, there is obviously a whole world of color that artists think about. Here we are in the color mastering suite. The equipment that we use is basically a supercomputer version of Photoshop, but it kinda looks a little bit like the Star Trek Enterprise. My goal in this lesson is to show you that color is really part physics and part human perception, and at the end of this lesson, you'll have a chance to manipulate the color using scenes from our films to achieve various artistic goals. But first we need to understand how the tools in this room work. So let's go back to a simple question. What is color? Color is a property of light, and light comes from light sources. And there are all different kinds of light sources. For example, I'm currently being lit by these lamps. Without these, our scene would look very different. And using a flame as our light source, like these two candles, really changes the feel of the scene. The light is not only dimmer, but it emits a reddish-orange light. Seeing this light on a white piece of paper is a great way to show this. Try pausing this video and hold your own white piece of paper up to the screen beside mine. Notice the difference between my white paper and yours. They're not the same, right? Now compare how the same piece of paper looks under the most powerful light source in the solar system, the sun. The sun gives off really intense light, especially in the middle of the day. You can clearly see that the light on this paper is much whiter than the candle light. Inside, the light was more reddish. So, where did the red light go? Let's go back inside so I can show you what happened. The key is to think of all light as a mixture of colors. Sir Isaac Newton famously demonstrated this when he used a glass prism to break up sunlight. When sunlight passes in and out of the prism, it bends, or refracts, and splits up into a spectrum of colors. After Newton, other scientists discovered that the light's wavelength is what determines how much it will refract, and what color it will be. Bluer light has a shorter wavelength and bends more. Redder light, with longer wavelengths, bends less. And this is the key point. Sunlight looks white because it contains all visible colors. Scientists have developed a 2-D graph to easily visualize the colors contained in any given light source. In this graph, along the X-axis, is the wavelength, and along the Y-axis is the intensity of that wavelength. For example, here's the graph of what daylight looks like. This is known as the spectrum of daylight. And a graph like this is called a spectral power distribution. And here's the spectral power distribution of candlelight. Notice it doesn't contain the same intensity of blue and green wavelengths. If we shine candlelight through a prism, we can't see a full rainbow. The reds are strong, but the blue wavelengths are much weaker. Is this first exercise, you'll have a chance to explore the spectrum of various light sources, and answer some questions about them. For example, what do you think the spectrum of a laser would look like?