m a p s meaningful applications of physical science email: map@sciencescene
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M A P s Meaningful Applications of Physical Science Email: [email protected]. Color. Presented By: The MAPs Team. Meaningful Applications of Physical Science Email: [email protected]. A. Summary of Waves Properties B. The Physiology of the Eye C. Perception - PowerPoint PPT PresentationTRANSCRIPT
M A PM A P ssMeaningful Applications of Physical ScienceEmail: [email protected]
A. Summary of Waves Properties
B. The Physiology of the Eye
C. Perception
D. The Spectrum of Light
E. Color Addition
F. Color Subtraction
G. Color Perception Revisited
A. Summary of Waves Properties
B. The Physiology of the Eye
1. Observing Our Eyes . . . . . . . . . . . . . . . . . . . . 3
2. How Far To The Side Can You See Color? . . . 8
3. Can You Find Your Blind Spot? . . . . . . . . . . . 11
4. Can You See Your Retina? . . . . . . . . . . . . . . . 13
5. Color Blindness . . . . . . . . . . . . . . . . . . . . . . . .
6. The Eye And Vision . . . . . . . . . . . . . . . . . . . . . 15
C. Perception
1. What is Visual Memory?. . . . . . . . . . . . . . . . . . . . 19
2. Can You Identify The Mystery Picture? . . . . . . . 21
3. How Long Can Your Eye Hold an Image? . . . . . 23
4. Producing A Ghost Image . . . . . . . . . . . . . . . . . . 26
5. Why Do We Need Two Eyes . . . . . . . . . . . . . . . . 27
6. Optical Illusions . . . . . . . . . . . . . . . . . . . . . . . . . . 29
D. The Spectrum of Light
1. Using a Prism to Separate White Light . . . . . . . . . . . . . . . . . . 37
2. Using A Diffraction Grating to Separate White Light . . . . . . . . 42
3. Using a Diffraction Grating to Identify Light Sources . . . . . . .48
4. The Illuminated Color Spectrum . . . . . . . . . . . . . . . . . . . . . . . .49
5. Frozen Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
6. How We See Color? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
E. Color Addition – Three Methods
1. Overlapping colored lights on a white surface
a. What Happens When Colors of Light Are Mixed? . . . . . . . . . 56
b. What are Complementary Colors? . . . . . . . . . . . . . . . . . . . . 58
c. What Are Colored Shadows? . . . . . . . . . . . . . . . . . . . . . . . . 59
d. Investigating Color Using a Diffraction Grating . . . . . . . . . . . 60
2. Placing very small areas of color very close together
a. Observing the Color on a TV Screen . . . . . . . . . . . . . . . . . . 61
b. Observing Newspaper Pictures . . . . . . . . . . . . . . . . . . . . . . . 65
3. Presenting colors in rapid succession.
a. Color Mixing on a Moving Disk . . . . . . . . . . . . . . . . . . . . . . .67
4. What are Afterimages? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5. Summarizing The Three Methods For Color Addition
F. Color Subtraction – Three Methods
1. Using Filters to Produce Color
a. What is the Effect of Colored Filters on Colored Light? . . . . . 82
b. What Happens When You Mix/Overlap Colored Filters? . . . . 88
c. What is the Effect of Colored Filters on Pigments? . . . . . . . . . 91
d. How Are Colors Produced In Color Printing? . . . . . . . . . . . . . 92
2. Mixing Pigments
a. Color Chromatography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
b. Mixing Various Pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
3. Absorption of Colored light By Reflecting Surfaces
a. Absorption of Colored light by Pigments . . . . . . . . . . . . . . . . . 98
b. What Is The Color Of That Object? . . . . . . . . . . . . . . . . . . . . 101
4. Summarizing The Three Methods For Color Subtraction . . . . . . .103
G. Color Perception Revisited
What Do you See When the Black and White Disk Spins? . . . 106
We Had A Great Time
I. Characteristics Of A Wave
A. Pulse: a single disturbance in a medium.
B. Frequency: the number of occurrences of some event per unit of
time.
(example; the number of times the meter stick goes up and down in one minute.)
C. Amplitude: the measurement of the distance the medium moves from
the
zero point to the maximum displacement. (example; the distance of the
very end of the meter stick - from standing still to the farthest distance away from
that zero position.)
D. Wavelength: the distance along a wave front — from any starting
point
to the next successive starting point. (example; looking at a slinky in motion.
Begin with the very beginning of a pulse to the very beginning of the next pulse.)
E. Loudness: occurs with the addition of energy to the vibrating
medium.
Summary of Wave Properties
4
Wavelength
Period = .5-sec.
Time = 1 sec
Frequency = 2 Hz
Amplitude
Five Basic Characteristics of Waves
1. Wavelength (l), is the distance from a point on a wave to the next point
2. Amplitude (A), is the maximum displacement. Amplitude indicates the loudness of a sound.
3. Period (t), is the time (in seconds) that it takes for a wave to travel one full wavelength.
4. Frequency (f), is the number of vibrations (waves) per second. This indicates the pitch of a sound.
5. Wave speed (V), is the rate the wave is traveling; the units of measurement are meters/sec.
3
Components Of Waves
II. Components Of Light and Sound waves
A Energy is needed to form any Light or Sound wave.
B Light waves are made by continuous succession of oscillating magnetic and
electric fields. These fields travel as a wave, an EM (Electromagnetic) wave.
C. Sound waves are made by the vibrations (moving back and forth) of
the particles of an object.
D. A medium is NOT needed to transport the Light energy.
E. A medium is needed to transport the Sound energy.
F. Waves are formed when energy is transported from one place to another.
2
III. Three Types Of WavesA. Torsional waves when the disturbance occurs as a twisting effect in a plane that is perpendicular to the direction on the wave motion (examples: twisters, hurricanes, tornados).
B. Longitudinal waves when the disturbance occurs in the same direction of the wave motion. (examples: sound, people standing in line, cars taking off from one red light and coming to a stop at another red light.)
C. Transversal waves when the disturbance occurs at right angles to the direction of the wave motion. (examples: water, light, radio, electromagnetic.)
Three Types Of Waves
1
Illustrating Wave Models
0
Electron Excitation and Emission http://micro.magnet.fsu.edu/primer/java/fluorescence/exciteemit/
0
The Physiology of the Eye
1. The pupil of the eye is a black object or spot on the surface of the eye.
2. It is possible to hold one's eyes perfectly still.
3. The eye receives upright images.
4. The lens is the only part of the eye responsible for focusing light
5. The lens forms an image (picture) on the retina. The brain then "looks"
at this image, and that is how we see.
6. The eye is the only organ necessary for sight; the brain is only for
thinking.
Naive Ideas:
5
Observing Our Eyes
1. Use the mirror to look at one of your eyes. Draw what you see on the index card (or paper). Put in as many details as you can. Use crayons or pencils to lightly color the drawings.
2. Label any parts of your eye that you know.
3. Compare your drawing of the eye with your partner's drawing. Describe how they are alike or different.
Materials: mirror, index card or sheets of paper, crayons. markers or colored pencils
How Far to the Side Can You See Color?
1. Have your partner select a piece, of colored paper and stand at your right side, a few steps away. He/she must not show you the color of the paper selected.
2. Focus your eyes straight ahead on an object across the room. Try to keep looking at this object all during the activity.
3. Have your partner slowly move the colored paper forward in a circle around you. Say "stop" when you can first absolutely determine the color of the paper. Identify where your partner was located (in degrees) when you determined the color of the paper?
4. Repeat this process for other colors also include black and white paper.
Red
Blue
Green
Black
White
Find your blind spot
Close your left and eye and just focus your right eye on the cross. At some point the big circle will disappear as it crosses your 'blind spot'. You may be surprised to see that the dot is replaced, not by a black region, but rather blank white space. The brain simply "fills in" the most probable stimulus (in this case, a uniform white area) where there is none
Can You See Your Retina?1. Close your eyes. Gently place a penlight against the outer corner of your
upper eyelid.
2. Wiggle your penlight back and forth or move it quickly in a small circle for several minutes.
3. When you find the right place, you will see a pattern of dark lines. These wavy lines are the shadows of the blood vessels in your eye on the retina.
4. Draw the pattern you see.
About 12 - 20 percent of white males and a tiny fraction of females are color blind.
Normal Color Vision Red-Green Color Blind Left Middle Right Left Middle RightTop 25 29 45 25 Spots SpotsBottom 56 6 8 56 Spots Spots
Color BlindnessIshihara Test for Color Blindness
1
The Eye and Vision
Structure of the Retina
Perception
1. The only purpose for having two eyes is to give a wide field of vision.
2. Memory plays an important role in the process of visual perception.
3. The eye-brain system can retain an image a for long time after the stimulus is removed.
4. The perception of depth occurs mainly within our brain.
5. Visual illusions occur when an illustration is perceived incorrectly or can be interpreted in more than one way due to a problem in ones vision.
Naive ideas:
4
Visual Memory - Seeing is a Complex Process
It is in your mind that the act of seeing takes place. Your brain puts together the nerve impulses from your eyes along with information from your brain. These interacting stimuli act together to become the picture that you see. Look at the following chart and say the color not the word.
1
Visual Memory
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1. Using common colored objects such as fur, screws, bolts, steel wool, sponges and colored wood blocks. Place the objects in a bag.
2. One student should be the investigator, and the other student should be the recorder.
3. The investigator should obtain the following to help describe the object.
Questions Answers
What shape is it?
What material is it?
What else can you tell about this object?
what color it is?
Name the object?
3
Can You Identify The Mystery Picture?
1
1
Can You Identify The Mystery Picture?
30
How Long Can Your Eye Hold An Image?
1. Draw a picture of a bird in the middle of one card.2. On the second card, draw a cage for the bird Be sure that the cage
will fit over the bird. You can check this. If the cards are the same size, hold the two cards up to a light. Does the bird fit inside the cage?
3. Tape the straw or pencil securely to the back side of one card so that the picture is oriented in a "right-side up" position. Working with a partner. tape all 4 edges of the second card to the first card so that both pictures are facing out and in the same orientation.
Producing A Ghost Image
Set up a projector and aim it toward an open door (or toward an open area of the room). Turn off the room lights. Hold a piece of paper in front of the slide projector and focus the projector to produce a clear image of the slide. Students should be behind the projector. Take the long stick and wave it rapidly in the same plane that the paper had been. Students should now be able to see the entire image!
White Stick
Why Do We Need Two Eyes?
Place a sharpened pencil in each hand and hold them apart at arm's length so that the sharpened ends face each other. Now with both eyes open, bring the pencils slowly toward each other and try to touch the points together. Describe what happens.
Illusions trick us into perceiving something differently than it actually exists, so what we see does not correspond to physical reality. The word illusion comes from the Latin verb illudere meaning, "to mock."
O p t i c a l I l l u s i o n s
Categories of Optical Illusions
1. Contrast
2. Convergence/Divergence
3. Bisection - Size
4. Pattern Completion
5. Relationships With Lines
6. Depth and Distance – Perspective
7. Isometric Or 3-D Drawings
8. Static Motion / Oscillation
9. Animation
10. Optical Illusions In Art
Contrast or Space – Are the Circles the Same?
The diagram features two circles with different surroundings. The two circles, in the center, are identical?1
7
Contrast or Space – Exaggerating the Contrast
The circles appear to be progressively lighter as you move to the right - but they're actually all the same shade of gray! Your brain tends to exaggerate the contrast between the circles and the background, so that the same circle appears darker against a light background, and lighter against a dark background. 1 6
Contrast – Which Semicircle is Brighter?
Which semicircle is brighter - the left or the right? 15
Contrast or Space – Are all Four Blue Dots the Same?
Viewing two colors at the same time influences both of their appearances. occurs when colors are used. Note that identical blue circles in the middle of different colors are influenced by their surrounding.
1 4
Contrast – Which Butterfly Appears Red?
23
Contrast – The inside red appears to be purple.
“Karakasa”
2
Contrast or Irradiation – Do the Intersections of the White Stripes Have Dark Blotches?
Irradiation Illusion occurs when light and dark regions are together. The eye's structure causes the image of the dark region on the retina to radiate into the light region. Your eyes "fill-in" the white intersections with the black of the background. 1
Contrast or Irradiation – The Blinking Effect
Your eyes make an attempting to "fill-in" the white circle intersections with the black of the background. Quite an amazing effect!
Instructions: Stare at the white circles and notice the intermittent blinking effect.
0
Objects of the same size appear unequal. This illusion is created by angles or segments which lead our eyes inward or outward, and thus shorten or lengthen an object.
Convergence/DivergenceMuller – Lyer Illusion
Are the Red and Blue Line The Same Length?
10
Bisection – Size Which Figure Has an Equal Height and Width?
5 Bisection illusion is created by the location of a vertical object over a horizontal object. The horizontal object is made to appear shorter. 7
Bisection – Size The Height and With of the Blue hat, Not the Red Hat, is Equal
26
Bisection – Size Is the Blue Line in Each Drawing The Same?
15
Bisection – Size Stars and Diamonds
Does the distance between the tip of the star and the tip of a diamond equal the length of a diamond?
1
4
Bisection – Size Does the Face of Each Lens Have the Same Curvature?
2
3
Bisection – Size Tri-curveEach of the 3 curves shown below are sections of a circle. If each section was completed into a circle which circle would be the largest?
They're all the same size
52
Bisection – Size Which Figure is Bigger?
11
Bisection – Size Which line is longer?
Which line is longer; A to B, or from B to C?
A C
B
20
Pattern Completion
Looking at this figure, you probably have a distinct impression of seeing a square. Now, cover up two of the “circles" at two opposite corners of the square. What happens?
This illusion shows that your brain performs pattern completion, and perceives complete objects, even when parts are missing.
3
Pattern Completion
Looking at this figure, you probably have a distinct impression of seeing a triangle. Now, cover up one of the three “circles". What happens?
2
Pattern Completion
1
Pattern Completion – The Ehrenstein “Street” Illusion
Ehrenstein’s lines create an interlocking grid of streets and circular intersections with the streets lying over the background. 0
Relationships With Lines Which line is Continuous With Line C
C
A
B1
The Cross Bar Illusion employs the use of a vertical lines or bars and diagonal line segments. The illusion is in determining which segments a line with each other The Poggendorf illusion, or `crossed bar' illusion invites us to judge which line, A or B, is aligned exactly with C. A good ruler can be used on the printed copy to check your answer.
9
Relationships With Lines - Skewed linesZollner Illusion
All these tracks are perfectly parallel! To prove they are parallel, watch the small ‘lines' gradually disappear. You will see the lines as how you would expect them to be. 8
Relationships With Lines - Skewed linesZollner Illusion
All these tracks are perfectly parallel! To prove they are parallel, watch the small ‘lines' gradually disappear. You will see the lines as how you would expect them to be. 7
Relationships With Lines Are the Red Lines Straight and Parallel?
1 Makes parallel lines appear non-parallel by using diagonal segments to intersect the parallel lines at different angles.
6
Relationships With Lines - Parallel Lines?
25
Relationships With Lines Are The Lines Parallel ?
14
Relationships With Lines - A Bulge
The lines in this picture are parallel.3
3
Relationships With Lines
The RED figure is actually a true circle.
1 2
Relationships With Lines Wagon Wheel Illusion
The "wagon wheel illusion". The shape superimposed on the wheel is actually a perfect square.
11
Relationships With Lines Do The Red Lines Form True Squares?
10
Depth and Distance – Perspective Are All Three Telegraph Poles The Same Size?
2
When identical objects are placed in different locations in a perspective drawing, the ob jects are made to appear different in size,
1
Depth and Distance – Perspective The Movie Theater
1 Are the Two Green Lines the Same Size?0
Isometric Or 3-D Drawings (Impossible Figures)
Two-dimensional drawings (on a flat surface) made to convey an illusion of three dimensional reality. Upon close observation these drawings reveal internal contradictions that could not exist in reality.
5
Isometric Or 3-D Drawings (Impossible Figures)
Two-dimensional drawings (on a flat surface) made to convey an illusion of three dimensional reality. Upon close observation these drawings reveal internal contradictions that could not exist in reality.
4
Isometric Or 3-D Drawings (Impossible Figures)
3
Isometric Or 3-D Drawings (Impossible Figures)
2
Isometric Or 3-D Drawings (Impossible Figures) Oscar Reutervars artwork used on Swedish Postage Stamp
1
Isometric Or 3-D Drawings (Impossible Figures)
Ambiguous Ring, By Donald E. Simanek
0
Static Motion – Can You Look Through Each End of this Spring?
6
Static Motion – Necker’s Cube
5
Static Motion – Can You Look up and Down the Stairs?
4
Static Motion – This Figure Can Appear In At Least 8 Different Ways
3
Static Motion – Shimmer
Your eye movements make this design seem to shimmer. You can get a stronger shimmer effect by moving your head as you stare at the design. The motion you see is not in the design, but in your own eye. Even though you're not aware of it, your eyes are constantly making small, jittering movements, which continually refresh the image cast on the back of your eye. Normally, your brain can ignore this motion, so your picture of the world stays stable.Each time your eye moves, the old image is briefly superimposed on the new image in your eye. When your eye moves over the repeating, evenly spaced lines of this design, the old and new images are superimposed to create a swirling shimmer.
2
Static Motion – The Moving Rings
1
Static Motion – Moving Snakes
The picture is not animated. Your eyes are making it move. To test this, stare at one spot for a couple seconds and everything will stop moving. Or look at the black center of each circle and it will stop moving.
0
Animation - Wheel of Confusion
Focus on the red dots the wheel appears to be rotating counterclockwise. However, if you focus on the yellow dots the wheel appears to be turning the other way! 2
Animation -
1
Animation - Rotating Skelton
Stare at the shadow of the rotating skeleton. You will notice that the skeleton appears to be rotating in one direction, and then, all of a sudden, will appear to rotating in the opposite direction. However, it’s all in your head. 0
Optical Illusions In Art - Princess or Old Woman?
8
Optical Illusions In Art - Do You See Five People?
7
Optical Illusions In Art - Old or Young Woman?First Done By: W. E. Hill
6
Optical Illusions In Art – Man Playing a Horn or Woman's Face?
5
Optical Illusions In Art – Indian Chief or Eskimo?
4
Optical Illusions In Art – How Many Horses?
3
Optical Illusions In Art – The Terrace
2
Optical Illusions In Art – The Waterfall By: Escher
1
Optical Illusions In Art - How Many?
Count the people in the picture above.Then wait till they shift, and count them again!
0
End of Optical Illusions
The Spectrum of Light
1. A white light source, such as an incandescent a fluorescent bulb, produces light made up of only one color. (All activities address this idea).
2. Sunlight is different from other sources of light because it contains no color.
3. When white light passes through a prism, color is added to the light.
Naive Ideas:
2
Using a Prism to Separate White Light
Using A Diffraction Grating to Separate White Light
The Electromagnetic Spectrum
2
Spectrum A Spectrum B Spectrum C
Spectrum D Spectrum E Spectrum F
Spectrum G
Name of Spectrum A Name of Spectrum B
Name of Spectrum C Name of Spectrum D
Name of Spectrum E Name of Spectrum F
Name of Spectrum G
Identify and name each spectrum shown below. The spectra will be: Fluorescent, Incandescent, Sodium, Neon, Krypton, Mercury, or Hydrogen. To identify them, observe them, use textbooks or internet, and match the reference spectrum to the spectra pictured below.
Fluorescent
Krypton
Mercury
Hydrogen
Neon
Incandescent
Sodium1
Using a Diffraction Grating to Identify Light Sources
1
Elemental Spectrum
Elemental Spectrum
http://jersey.uoregon.edu/elements/Elements.html(Produces a spectrum of any element)
0
Light Sources
Fluorescent Incandescent
SodiumNeon
Krypton Mercury
Hydrogen
TheIlluminated Spectrum
The Luminated Color Spectrum
A colored spectrum can be made to “glow”showing individual colors of the spectrum.
Materials: Box of wax used for canning. Usually four pieces 4-inchex by 8-inches. One piece of holographic diffraction grating approximately 5-inches square, aluminum foil..
Cut the blocks by scoring the blockof wax with a knife. Hold the blockover the edge of a table and snap it.
Stack the blocks of cut wax on edge and placea piece of aluminum foil folded, with theshiney side out, between each block and oneach end.
Tapeholographicdiffraction
grating here.
Hold waxblock here.
Screen
Place two sheets ofopaque paper with asmall slit in between forthe light to to pass.
Turn on the overhead with the paperand slit and the diffraction grating.Adjust the color spectrum so that itshines on the screen. Adjust the blockof wax in the beam of light in front ofthe spectrum until the blocks appear toglow. Each block internally reflects acolor of the spectrum producing an evenband of the color within the individualblock.
Holographic diffraction grating waspurchased from:
Learning Technologies Inc. 59 Walden Street Cambridge, MA 02140
The Frozen Spectrum
Place the paper in the bottom of the pan and fill the pan with water to cover the paper with at least a half of an inch of water.
Drop a single drop of nail polish onto the surface of the water.
The nail polish drop will quickly expand to make a circle of film on the water. This film will be so thin, that it will only be as thick as one wavelength of light.
Let the nail polish dry for a few minutes then gently lift one end of the paper out of the water. Let the water drip off the paper and then set onto some newspaper to dry.
To view the colors, hold the paper flat towards the light, and view it at a low angle.
How We See Color - Responses Of Cone Cells As A Function Of Wavelength
BlueSensitiveCones
GreenSensitiveCones
RedSensitiveCones
RelativeResponseOf Cones
400 450 500 550 600 650 700 Wavelength of light (nm)
Violet Blue Green Yellow Orange Red
Color Addition
Color subtraction can be observed under three conditions:
1. Mixing of Colored Lights
2. Small Patches/Dots of color
3. Movement
Color Addition
l. The rules for mixing color paints and crayons are the same as the rules for mixing colored lights.
2. The primary colors for mixing colored lights are red, blue and yellow.
3. A colored light striking an object produces a shadow behind it that is the same color as the light. When red light strikes an object, a red shadow is formed.
4. The shades of gray in a black and white newspaper picture are produced by using inks with different shades of gray.
Naive Ideas:
3
What Happens When Colors of Light Are Mixed?
1
Color Addition - Simulator
0
What are Complementary Colors?
11 1
Complementary ColorsTable
What are ComplementaryWhat Added Color Will Make White?
BlueYellow
GreenMagenta
RedCyan
MagentaGreen
YellowBlue
CyanRed
Actual Complement Complement Predicted
Light
18
Complementary Colors
Can You See Magenta’s Complement
0
What Are Colored Shadows?
1
Colors ShadowsTable
What Are Colored Shadows?
Cyan, Magenta, YellowWhite
Red, GreenYellow
Red, BlueMagenta
Blue, Green Cyan
GreenGreen
BlueBlue
RedRed
List Each Shadow's Color(s)Light
07
Colored Shadows
Investigating Color Using a Diffraction Grating
1
Colors - Diffraction
Grating Table
Components Of Primary And Secondary Colors
Red, GreenYellow
Red, BlueMagenta
Blue, GreenCyan
GreenGreen
BlueBlue
RedRed
Main Color(s) Observed Using a Diffraction GratingLight
Investigating Color Using a Diffraction Grating
0
6
Colors – Diffraction
Grating
Color picture tubes have three electron beams and phosphors that emit red, green, and blue light. Mixtures of red, green, and blue light appears full color by carefully mixing these three colored lights. The inside surface of a color television screen is coated with thousands of tiny red blue and green phosphor dots. Each colored dot, in the set, is either on, off or dim. The colors of a television picture depend upon the set of these three color phosphor dots. You will notice all three colored dots can be seen, but the pattern of on, off and dim create the televisions picture.
The television directs electrons at these dots through holes in a metal mask. Three separate electron beams, coming from three slightly different angles, pass through the holes and strike the phosphors. Since each beam can only strike one color of phosphor dots, each beam con trols the brightness of one of the three colors.
A picture is produced when many thousand of the dots are hit with the electron beams in a specific pattern. If one magnifies a TV picture they would observe the tiny dots that make up the picture. The colors produced on the screen may be described by “Color Addition”
How Television Color WorksPlacing Small Areas of Color Close Together
1
Color Wheel as Seen on a Television Screen
ON ON ONWhite
OFF OFF OFF Black
ON ON OFFCyan
OFF ON ONYellow
ON OFF ONMagenta
OFF ON OFFGreen
ON OFF OFFBlue
OFF OFF ONRed
ActualPredictedActualPredictedActualPredictedColor Wheel
Blue RectangleGreen RectangleRed RectangleColor On
Brightness of individual dots, on TV, magnified 7X
How Television Color WorksPlacing Small Areas of Color Close Together
0
8
Newspaper Pictures - Black and White
3
Newspaper Pictures – Colored Pictures
2
Colored Picture - Baby
Placing Small Areas of Color Close Together
1
Original Image 100% scale 200% scale
400% scale 800% scale
Placing Small Areas of Color Close Together
0
Presenting Colors in Rapid Succession
Color Movement - Spinning Disks
1
Color Movement - Using the "Spinning Disks"
White Newton's Color Wheel
Yellow half green + half red
Cyan half green + half blue
Magentahalf blue + half red
Actual colorPredictionOriginal colors
Presenting Colors in Rapid Succession
0
4
What are Afterimages? - The Light Bulb
One of the best known visual effects is the afterimage. If one stares at the Bulb for 30-seconds then looks at the white area to the right they will see a patch of color that is the complement of the original color.
4
What are Afterimages? - Queen Elizabeth II
Instructions: Stare at the picture (on the left) for about 45 seconds. Then, stare at the white section of this image (the right section). You should see the Queen again.
3
What are Afterimages? - Fish in a Bowl
22
What are Afterimages? - Bird in a Cage
Stare at the eye of the red parrot while you count slowly to 20, then look immediately at one spot in the empty birdcage. The faint, ghostly image of the blue-green bird will appear in the cage.
Try the same thing with the green cardinal. A faint magenta bird will appear in the cage.
1
What are Afterimages? – American Flag
0
Color Addition
Color subtraction can be observed under three conditions:
1. Mixing of Colored Lights
2. Small Patches/Dots of color
3. Movement
Color Subtraction
1. When white light passes through a colored filter, the filter adds color to the light.
2. The different colors in magazines and newspapers pictures are produced by using different inks with all the corresponding colors
3. The mixing of colored paints, crayons, and pigments follow the same rules as the mixing of colored lights.
4. The primary colors used by artists (red, yellow, and blue) are the same as the primary colors for all color mixing.
5. Color is a property of an object, and is independent of both the illuminating light and the receiver (eye).
6. White light is colorless and clear, enabling you to see the "true" color of an object. Colored light is darker than white light and makes objects appear darker.
7. When a colored light illuminates a colored object, the coin of the light mixes with the color of the object.
Naive Ideas:
6
Color subtraction can be observed under three conditions:
1. Filters
2. Reflected Light
3. Pigments
In each case, the medium (reflecting surface, pigments, filter) affects or modifies the light before it reaches your eyes. In each case the process called color subtraction will allow us to predict the color we see.
RED
White Light (RBG) Red Light
-B -G
White light shines through a red filter. The red filter subtracts blue and green leaving red light that we see. White light (RBG) – B – G = red light
What is the Affect of Colored Filters?
1
The Effect of Colored Filters on Colored Light?
GBCGBBKRCyan
YRGGBKRBYellow
RMBBKBRGMagenta
GBKGGBKBKR,BGreen
BKBBBKBBKR,GBlue
RRBKBKBKRB,GRed
Color Seen
Color Seen
Color Seen
Color Seen
Color Seen
Color Seen
Yellow(R+G)
Magenta(R+B)
Cyan(B+G)
Green (G)
Blue (B)
Red (R)
Color of LightColor(s)
Subtractedby FilterFilter
1. Using an aquarium bulb and appropriate filter produce the color of light indicated in the table.
2. Predict the color seen through the filter after subtracting the colors subtracted by the filter.
3. Look at the light through the indicated filter to observe the color actually produced.
36
0
What is the Effect of Mixing Colored Filters?
Cyan MagentaWhite Light – Red – Green = Blue
Cyan YellowWhite Light – Red – Blue = Green
Magenta YellowWhite Light – Green – Blue = Red
Magenta Yellow CyanWhite Light – Green – Red – Blue = Black
212
White Light (RBG) Yellow Light (RG)
-B
Green Light (G)
-R
YELLOW
CYAN
WL (–B) (–R) = G
Mixing Filters to Produce Colors
1
The Effect of Colored Filters On Viewing
Black(R) (B) (G)Cyan + Yellow + MagentaR + B + G
Green(R) (R,B)Cyan + GreenR + B + G
Blue(R) (R,G)Cyan + BlueR + B + G
Black (R) (B,G) Cyan + RedR + B + G
Green(B) (R)Yellow + CyanR + B + G
Green(B) (B,R)Yellow + GreenR + B + G
Blue(G) (R)Magenta + CyanR + B + G
Red(G) (B)Magenta + YellowR + B + G
Black (G) (R,B)Magenta + GreenR + B + G
Red (G) (B,G)Magenta + RedR + B + G
Blue(G) (R,G)Magenta + BlueR + B + G
Black(B,G) (R,G)Red + BlueR + B + G
ObservedPredictedSubtractedFilter ColorLight Color
Color
Overlap filters, as indicated, while looking at a piece of white paper. Mixing Colored Filters
240
What is the Effect of Colored Filters on Pigments?
42
CGBGBBKCyan Filter (B,G)
GYRGBKRYellow Filter (R,G)
BRMBKBRMagenta Filter (B,R)
GGBKGBKBKGreen Filter (G)
BBKBBKBBKBlue Filter (B)
BKRRBKBKRRed Filter (R)
CYMGBRWhite light (R,B,G)
Color SeenPredictionColor
SeenPredictionColor SeenPredictionColor
SeenPredictionColor SeenPredictionColor
SeenPrediction
Cyan (R)Yellow (B)Magenta (G)Green (B,R)Blue (R,G)Red (B,G) Light/ FilterUsed to
Illuminate
Absorption or Subtraction By Colored Pigments (Subtracted Color(s))
Looking at the "Color Wheel" predict and observe the color produced when looking through the filter indicated in the data table.
0
Color Wheel
Color Wheel and Red Filter
Color Wheel and Blue Filter
Color Wheel and Green Filter
Color Wheel and Cyan Filter
Color Wheel and Magenta Filter
Color Wheel and Yellow Filter
Color Wheel
Chart
White Light (RBG) Yellow Light (RG)
-B
Red Light (R)
-B -G
Red Light (G)
-G
MAGENTA
Color Subtraction - Using Filters to Produce Colors
0
How Are Colored Pictures Produced in Color Printing?
Marker Color
Predicted Color(s) Actual Color(s)
Black
Green
1. Draw a line across a strip of the chromatography paper with the black marker approximately 1.0-cm from one end of the paper.
2. Predict what colors make up the black marker.
3. Place four to six drops of water near the end of the paper with the marker and allow it to 'develop' for a few minutes.
4. Predict what colors would make up the green marker.
5. Repeat the procedure for the green marker. Record the actual colors observed in the data sheet.
Color Chromatography - Pigments
What is the Effect of Mixing Colored Pigments?
Color Subtraction - Simulator
5
What is the Effect of Mixing Colored Pigments?
Color Subtraction - Simulator
4http://www.ontariosciencecentre.ca/scizone/games/subtracting/default.asp
Mixing Pigments – C,M,Y
3
Mixing Pigments – C,M
2
Mixing Pigments – C,Y
1
Mixing Pigments – M,Y
0
Absorption of Color by Pigments
6
CGBGBBKCyan Filter (B,G)
GYRGBKRYellow Filter (R,G)
BRMBKBRMagenta Filter (B,R)
GGBKGBKBKGreen Filter (G)
BBKBBKBBKBlue Filter (B)
BKRRBKBKRRed Filter (R)
CYMGBRWhite light (R,B,G)
Color SeenPredictionColor
SeenPredictionColor SeenPredictionColor
SeenPredictionColor SeenPredictionColor
SeenPrediction
Cyan (R)Yellow (B)Magenta (G)Green (B,R)Blue (R,G)Red (B,G) Light/ FilterUsed to
Illuminate
Absorption or Subtraction By Colored Pigments (Subtracted Color(s))
Observing the "Color Wheel" predict then observe the color produced when looking at a pigment.
What Is The Color Of That Object?
Color subtraction can be observed under three conditions:
1. Filters
2. Reflected Light
3. Pigments
In each case, the medium (reflecting surface, pigments, filter) affects or modifies the light before it reaches your eyes. In each case the process called color subtraction will allow us to predict the color we see.
Color Perception Revisited
Color perception involves only the properties of the objects being observed, and not the properties of the eye-brain system.
Naive Ideas:
G. Color Perception Revisited - Benham Disks
We Had A Great Time