2 Spectrum of Light2 7 Mixing Colors by Addition7 2222 Mixing Colors by Subtraction – Define 2727...

2 Spectrum of Light 7 Mixing Colors by Addition22 Mixing Colors by Subtraction – Define27 Colored Filters45 Primary Colors from C, M, Y48 Color Printing51 Mixing Paints56 Physicists vs Artists60 Illuminating Using Colored Light

Investigating Color

CreatedBy

Dick Heckathorn1 April 2K+2

I. The Spectrum of Light

A. White light can be separated into different colored lights called the spectrum.

1. Inv: How Can A Prism Be Used to Separate White Light Into Its Component Colors?

a. Look through a prism.

b. Shine ray of light into prism

c. Rotate prism as light passes through.

I. The Spectrum of Light

A. White light can be separated into different colored lights called the spectrum.

2. Demo-Disc: What Does the Prism Do to the Light?

a. Shine light from aluminum slide through a prism.

b. Block out all but red light.

c. Add second prism.

d. Mount second prism behind first.

I. The Spectrum of Light

A. White light can be separated into different colored lights called the spectrum.

3. How Does a Diffraction Grating Be Used to Separate White Light Into Its Component Colors?

a. Look through a grating at showcase bulb

I. The Spectrum of Light

A. White light can be separated into different colored lights called the spectrum.

3. How Does a Diffraction Grating Be Used to Separate White Light Into Its Component Colors?

b. Look at spectrum using cardboard with slit on overhead and with grating fastened to overhead lens.

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Happens When Colors of Light Are Mixed?

a. Have students perform color addition using ray boxes.

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Happens When Colors of Light Are Mixed?

b. Overlap colors using projector and 3 mirrors

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Happens When Colors of Light Are Mixed?

c. Mount color wheel on wall.

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Happens When Primary Colors Of Light Are Mixed?

R + G ____

R + B ____

G + B ____

Yellow

Magenta

Cyan

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Happens When Opposite Colors Of Light Are Mixed?

B + Y ____

R + C ____

G + M ____

White

White

White

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Happens When Opposite Colors Of Light Are Mixed?

When two colors are added together that produces white light, we call them complementary colors.

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

2. What Are Colored Shadows?

a. Look at shadow produced using light from overhead or projector.

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

2. What Are Colored Shadows?

b. Look at shadow produced using two light bulbs separated by some distance.

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

2. What Are Colored Shadows?

c. Look at shadows produced using red, green and blue bulbs individually and in combinations of first 2 and then all three.

II. Mixing Colors By Addition

A. Different colored lights overlapping on a white surface are perceived by the eye-brain system as the additive combination of the individual colors.

2. What Are Colored Shadows?

d. Quiz

II. Mixing Colors By Addition

B. Very small and closely spaced areas of color are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Do Colors On A Color TV Screen Look Like Up Close?

a. Freeze a colored video on a TV screen.

b. Investigate using a lens.

II. Mixing Colors By Addition

B. Very small and closely spaced areas of color are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Do Colors Of A Comic Strip Look Like Up Close?

a. Investigate using a magnifying lens.

II. Mixing Colors By Addition

B. Very small and closely spaced areas of color are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Do Colors Of Colored Objects In Your Text Look Like?

b. Investigate using a magnifying lens.

II. Mixing Colors By Addition

B. Very small and closely spaced areas of color are perceived by the eye-brain system as the additive combination of the individual colors.

1. What Do Black And White Pictures In A Newspaper Look Like?

c. Investigate using a magnifying lens.

III. Mixing Colors By Subtraction

A. Colored lights and colored objects can be described in terms of three attributes: hue, saturation and brightness. 1. The Attributes of Color

a. Hue – Main Color NameA sensation

b. Saturation – Purity of ColorRich or pale – Strong or weak

c. Brightness – IntensityA sensation

III. Mixing Colors By Subtraction

A. Colored lights and colored objects can be described in terms of three attributes: hue, saturation and brightness. 1. Naming Colored Lights and Colored

Objects. a. What we perceive when:

• looking at the source or • an object illuminated by a

source• the object is illuminated with

white light

III. Mixing Colors By Subtraction

A. Colored lights and colored objects can be described in terms of three attributes: hue, saturation and brightness. 1. Naming Colored Lights and Colored

Objects. a. What we perceive when:

• the object is illuminated with any color of light.

Say the Color, not the Word

YELLOW BLUE ORANGE

BLACK RED GREEN

PURPLE YELLOW RED

ORANGE GREEN BLACK

BLUE RED PURPLE

GREEN BLUE ORANGE

Say the Color, not the Word

YELLOW BLUE ORANGE

BLACK RED GREEN

PURPLE YELLOW RED

ORANGE GREEN BLACK

BLUE RED PURPLE

GREEN BLUE ORANGE

Say the Color, not the WordYELLOW BLUE ORANGE

BLACK RED GREEN

PURPLE YELLOW RED

ORANGE GREEN BLACK

BLUE RED PURPLE

GREEN BLUE ORANGE

Left – Right Conflict within brainYour right brain tries to say the color but your left brain insists on reading the word.

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others. The name of the filter is determined by the color of light transmitted when white light is incident on the filter.

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

a. Look through one colored filter at a time while looking at white light.

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

Using:• cardboard with slit on projector• grating over projection lens• colored filters

Examine what R, G, B, filters do.

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

a. Look through red

White R + G + BRed - G -

B

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

b. Look through green

White R + G + BGreen -R - B

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

c. Look through blue

White R + G + BBlue -R - G

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

d. Look through red and green

Red - G - BGreen - B - R Black

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

e. Look through red and blue

Red - G - BBlue - G - R Black

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

g. Look through green and blue

Green - B - RBlue - G - R Black

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

Using cardboard with slit on projectorgrating over projection lenscolored filters

Examine what C, M, Y, filters do.

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

a. Look through Cyan

White R + G + BCyan - R

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

b. Look through Magenta

White R + G + BMagenta - G

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

c. Look through Yellow

White R + G + BYellow - B

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

d. Look through yellow and magenta

Yellow - BMagenta - GRed

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

e. Look through yellow and cyan

Yellow - BCyan - RGreen

III. Mixing Colors By Subtraction

B. A colored filter has the property of transmitting certain colors and absorbing others.1. What Do Colored Filters Do?

f. Look through magenta and cyan.

Magenta - GCyan - RBlue

III. Mixing Colors By Subtraction

B. A colored filter has the property of absorbing certain colors and transmitting others. 1. What Do Colored Filters Do?

g. Summarya. Yellow and Magentab. Yellow and Cyanc. Cyan and Magenta

RedGreen

Blue

Look at Color Power Point

III. Mixing Colors By Subtraction

C. The primary colors for mixing by subtraction are cyan, magenta and yellow.

1. Diagram For Overlapping Filters

Yellow Cyan

White - B Yellow - R = Green

(R+G+B) - B (R +G) - R = G

III. Mixing Colors By Subtraction

C. The primary colors for mixing by subtraction are cyan, magenta and yellow.

1. Diagram For Overlapping Filters.

Yellow Magenta

White - B Yellow - G = Red

(R+G+B) - B (R +G) - G = R

III. Mixing Colors By Subtraction

C. The primary colors for mixing by subtraction are cyan, magenta and yellow.

1. Diagrams For Overlapping Filters.

Magenta Cyan

White - G Magenta - R = Blue

(R+G+B) - G (R + B) - R = B

III. Mixing Colors By Subtraction

D. The primary colors used in the printing process are: cyan, magenta and yellow.

1. How is a colored picture made?

a. Color Poster

b. Show Picture of Garfield

III. Mixing Colors By Subtraction

E. The mixing of colored paints involves both additive and subtractive processes.

Predicting the resulting color is complicated because it depends on the physical properties of paints.

III. Mixing Colors By Subtraction

E. The mixing of colored paints involves both additive and subtractive processes.

1. The Mixing of Paints and the Artist's Primary Colors

The mixing of water colors and printers inks are similar to

“mixing” color filters.

III. Mixing Colors By Subtraction

E. The mixing of colored paints involves both additive and subtractive processes.

1. The Mixing of Paints and the Artist's Primary Colors

Mixing pigment-based paints are not so simple.

III. Mixing Colors By Subtraction

E. The mixing of colored paints involves both additive and subtractive processes.

1. The Mixing of Paints and the Artist's Primary Colors

Paint consists of tiny solid particles in a transparent medium.

The particles have no color or are clear with dye added

III. Mixing Colors By Subtraction

E. The mixing of colored paints involves both additive and subtractive processes.

1. The Mixing of Paints and the Artist's Primary Colors

Final result affected by

Density of ParticlesProperties of transparent

mediumSupport on which the paint is laid

III. Mixing Colors By Subtraction

F. The naming of the primary colors by physicists and artists differ.

The physicists primary colors of lightRed – Green – Blue

The physicists secondary colors of lightMagenta – Cyan – Yellow

The artist’s primary colors of pigmentsRed – Turquoise - Yellow

III. Mixing Colors By Subtraction

F. The naming of the primary colors by physicists and artists differ.

The physicists secondary colors of light Magenta – Cyan – Yellow The artist’s primary colors of pigments

Red – Blue – Yellow

Thus to a physicistArtists say Red - Physicists call magenta

Artists say Blue - Physicists call cyan

III. Mixing Colors By Subtraction

F. The naming of the primary colors by physicists and artists differ.

The physicists secondary colors of light Magenta – Cyan – Yellow The artist’s primary colors of pigments

Red – Blue – Yellow

Baggie Ad: Blue - Yellow Green Physicist: Cyan - Yellow Green

IV. What is the Color?

IV. The color an object appears depends on the color of the illuminating light and the properties of the object.

1. What Is The Color of That Object?

a. Shine colored light on colored cardboard.

IV. What is the Color?

IV. The color an object appears depends on the color of the illuminating light and the properties of the object.

1. What Is The Color of Red, Green, Blue on monitor or computer screen?

d. Use “red”, “green”, “blue” filter to view the screen.

Why do they appear as they do?

RedGreenBlue

IV. What is the Color?

IV. The color an object appears depends on the color of the illuminating light and the properties of the object.

c. Results seen with eye.

red green blue

red red red black red black

green blackgreen green green black

blue black blue black blue blue

IV. What is the Color?

IV. The color an object appears depends on the color of the illuminating light and the properties of the object.

1. What Is The Color of Red, Green, Blue using Felt Tip Markers?

b. Shine white light on the colors.

Why do they appear as they do?

IV. What is the Color?

IV. The color an object appears depends on the color of the illuminating light and the properties of the object.

e. Results viewing with filter?

red green blue

red red red black red black

green blackgreen green green black

blue black blue black blue blue

1. What are the colors of the letters?

V. Evaluation

2. Are you color blind?

1. Is it a green filter?

V. Things for Thought

2. What color is the baggie strips?

3. What color is the printing on

plastic?

That’s all folks!