1. TOPIC 4.3 SNC2P

3. Lesson Goals Today we will learn that: colours of light can be added together to form a variety of colours through two investigations. Pigments can subtract colours from light.

4. WWW.POLLEVERYWHERE.COM WHAT COLOURS DID YOU OBSERVE IN YESTERDAY’S ACTIVITY? IF YOUR HAVE A CELL PHONE, PLEASE TAKE IT OUT NOW... ITS TIME TO TEXT IN YOUR OBSERVATIONS! TEXT YOUR RESPONSES TO... 37607

5. ACTIVITY 4.4 RESULTS (Textbook P.300) OBSERVATIONS FILTER COLOURS ACTIVITY 4.4: TRICKING THE EYE ACTIVITY: SUNLIGHT & PADDLE COLOURS RED GREEN BLUE RED + GREEN RED + BLUE GREEN + BLUE RED + BLUE + GREEN

6. Did you know... That the millions of colours on a computer monitor or TV screen are produced with ONLY... 3 COLOURS!!

7. Recognizing Colours Your eyes have only 3 types of cells that can recognize millions of colours. When you observe a colour, it is because different combinations of these cells are stimulated. A TV screen uses a system of only three colours to create the effect of many different colours, just like the cells in your eyes.

8. Primary Colours PRIMARY COLOURS: Three colours that can be combined to create any other colour. Can be additive or subtractive. RED GREEN BLUE

9. Additive Primary Colours ADDITIVE PRIMARY COLOURS ARE: Red Green Blue These three colours of light are also known as primary colours.

10. Additive Primary Colours Creating different colours of light depend on the additive colour theory. When all 3 primary colours are combined, they make white light.

11. Additive Secondary Colours By combining only two of the primary colours, you will make a secondary colour. These are: Yellow Cyan Magenta

12. Complementary Colours Colours that are directly across from each other are complementary colours. Red & cyan Green & magenta Blue & yellow

13. Pigments can subtract colour from light When an object absorbs a colour, it removes (or subtracts) it from the beam of light. The colours of most of the objects that you observe every day are the result of subtracting colours. There are three subtractive primary colours: cyan, magenta, and yellow. A variety of combinations of these three colours can subtract light from white light to produce nearly any colour. Magenta, cyan, and yellow films subtracting colours from white light. What do you see when these three overlap?

14. The colours produced by subtracting equal amounts of two of the three subtractive primary colours are called subtractive secondary colours. The subtractive secondary colours are the same as the three additive primary colours (red, green, and blue).

15. When the three subtractive primary colours are added together and subtracted from white light, you get black. The “code” for black is K so as not to be confused with blue.

16. Subtractive Colour Theory of Light If a colour is absorbed, it will not make it to your eye. You only see the reflected colours. Paint and pigment manufacturers mix all three of the primary subtractive colours in varying degrees to make any range of colours reflect from a surface.

17. Primary pigments Yellow M agentaCyan Black

18. Colour Wheel The COLOUR WHEEL shows how all the colours are related.

19. Copyright © 2010 McGraw-Hill Ryerson Ltd. Tertiary colours are formed by mixing the secondary colours. The resulting colours are yellow-green, orange, crimson, cobalt, and turquoise. Colour Wheel

20. Copyright © 2010 McGraw-Hill Ryerson Ltd. The subtractive primary colours cyan, magenta, and yellow are the same as the additive secondary colours. Colour Wheel Relationships

21. Copyright © 2010 McGraw-Hill Ryerson Ltd. The additive primary colours red, green, and blue are the same as the subtractive secondary colours. Colour Wheel Relationships

22. Copyright © 2010 McGraw-Hill Ryerson Ltd. The colours that are directly across from each other on the colour wheel are complementary colours. When you add complementary colours, the result is white. When you subtract complementary colours, the result is black. Colour Wheel Relationships

23. Copyright © 2010 McGraw-Hill Ryerson Ltd. Diagrams can be used to show how colours are subtracted from white light when it hits a film of a certain colour. Using Diagrams to Illustrate Subtractive Colours

24. ACTIVITY 4.6 (Textbook P.301) In groups of 2 or 3: Complete the activity. Write your group members’ names on the paper. Create a table to record your results. Answer Questions #1-4 on page 301 Hand in the table as a group. Please write all group members names on the paper.