1. Additive vs. Subtractive There are two different ways to mix colors.

2. Additive vs. Subtractive What do you get if you use a prism to combine all wavelengths of light?

3. Additive vs. Subtractive What do you get if you use a prism to combine all wavelengths of light?

4. Additive vs. Subtractive What do you get if you mix a bunch of paint?

5. Additive vs. Subtractive What do you get if you mix a bunch of paint?

6. Additive vs. Subtractive

7. Additive mixing is most intuitive: ADD wavelengths: red+green = yellow red+blue = magenta blue+green = cyan red+green+blue=white

8. What color can only exist as a metamer (an additive mixture of wavelengths)? In other words, what color cannot be made with a single wavelength?

9. Magenta Think about why!

10. Subtractive mixing is much less intuitive (but much more common) Subtractive mixing happens when we mix pigments (paint) together Different pigments subtract different wavelengths: –red subtracts all but red, blue all but blue, green subtracts blue and red, etc…

11. Example: blue + yellow = green Technically it’s called “cyan”

12. The result of a mixture depends on what wavelengths don’t get absorbed by the two pigments wavelength Amount of filtering blue greenyellowred

13. Both yellow and blue pigments reflect a bit of green wavelength Amount of filtering blue greenyellowred

14. Subtractive mixing is commonly used in color printers

15. Everything you’ve learned so far is wrong.

16. Well, not really wrong, just far from complete.

17. Everything you’ve learned so far is wrong. Well, not really wrong, just far from complete. You will read in the article by Land that the color of a surface depends as much on the colors of the surrounding surfaces as it does on the wavelength of light it reflects.

18. Read article by Land