upcoming classes thursday, nov. 29 th making color (visual arts @ nexus) assignment due: * homework...
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Upcoming Classes
Thursday, Nov. 29th
Making Color (Visual Arts @ Nexus)
Assignment due:
* Homework #5 (Visiting the Exploratorium)
Tuesday, Dec. 4th
Third set of Oral Presentations
Assignment due:
* Last term paper or oral presentation
Thursday, Dec. 6th (Last day of class)
Making Holograms (Meet in Science Bldg, Room 133)
Assignment due:
* Homework #7 (Optical Instrument)
* Written summary of your MUSE workshop activities
Upcoming Deadlines
Tuesday, December 4th
Third Set of Oral Presentations
Third term paper (if not presenting)
Thursday, December 18th
Final Exam
Oral Presentations (III)
The following persons will give oral presentations on Tuesday, December 4th :
• Remmel, Katherine• Sugiura, Ayuka• Yamaguchi, Asuka• Zeber, Emily,• Dinh, Phiphi
For everyone else, term paper is due on that date.
Homework 5: Exploratorium
Due Thursday, November 29th
Extra Credit: San Jose Ballet
See a performance of San Jose Ballet in San Jose Center for Performing Arts (Nov. 15th – 18th ).
Turn in your ticket receipt. Worth one homework assignment or three quiz/participation credits.
Ramon Moreno in CARMINA BURANA
Extra Credit: San Jose Museum of Art
Visit the San Jose Museum of Art. Turn in yourticket receipt. Worth two quiz/participation credits.
Richard Diebenkorn, Untitled (Albuquerque), 1952 Joan Miró, Untitled from Paroles Peintes, 1967.
Final ExamThursday, December 18th, 1215-1430 Exam will have eight short essay questions (4-8
sentences).Final exam will be based on the reading
assignments and lecture topics since the midterm (see calendar).
The exam counts as two homework assignments (out of a total of nine).
May skip up to two homework assignments; if you don’t, I’ll drop the lowest scores.
Course Grade
The grade in the class is based on:
• First Term Paper
• Second Term Paper
• Oral Presentation
• In-class Participation (Quizzes, Activities)
• Homework (Final counts as 2 homeworks)
Each counts towards 20% of your grade
Quiz
The Shroud of Turin is probably not the burial cloth of Christ because
a) The pigment, burnt sienna, did not exist at the time of Christ
b) Carbon dating of the flax cloth marks it as being from the 14th century.
c) Computer reconstruction of the face reveals that the features are those of a woman.
d) Trace fibers of a plastic, nylon brush have been found in the image
e) None of the above.
Seeing Color
Spectrum of Visible Light
Wavelengths & Photons
Red Photon
Blue Photon
Green Photon
Yellow Photon
PrismSpectrum
Particles of light, called photons, each have a wavelength.
Newton’s Color Wheel
Prism spectrum is a straight line, so why did Isaac Newton describe color using a circular wheel?
Additive Color Wheel
SpectralColors
There are No
Photons of These Colors
R
Y
B G
M
C
RedYellowGreenCyanBlueMagenta
Adding Color Lights
Stream ofred & green photons looks same as yellow photons(metamerism)
Theatrical lighting
or
YELLO
W
Eye toBrain
Notice overlap of red, green, & blue is seen as whitewhite light
Trichromatic Theorists
Thomas Young
(1773-1829) English physicist
Hermann von Helmholtz (1821-1894)German physicist
James Clerk Maxwell(1831-1879)Scottish physicist
Simple Trichromatic TheoryYellow &
Redphotons
excite me
Yellow, Green &
Cyanphotons
excite me
Cyan &Blue
photons excite me
Inside your eye there are three receptors
MOECURLY
LARRY
Trichromatic: Seeing YellowYellow &
Redphotons
excite me. I’M
EXCITED
Yellow, Green &Cyan photons
excite me.I’M EXCITED
Cyan & Bluephotons
excite me.Yawn.
Yellow seen when Curly and Larry excited, either by yellow photons or red & green photons.
MOE
CURLYCURLY
LARRYOR
Seeing YellowSodium lamps emit pure yellow photons
Color monitor can only emit red, green, and blue (RGB); creates other colors by selectively turning RGB pixels on or off.
Trichromatic: Seeing MagentaYellow &
Redphotons
excite me. I’M
EXCITED
Yellow, Green &Cyan photons
excite me.Yawn.
Cyan & Bluephotons excite me.
I’M EXCITED
Magenta is seen by eye when Moe and Larry excited, which no single type of photon can achieve.
MOE
CURLYCURLY
LARRY
Maxwell Color Disk
Disk painted half red, half blue looks magenta when rapidly spinning.
Trichromatic: Seeing WhiteWhiteYellow &
Redphotons
excite me. I’M
EXCITED
Yellow, Green &Cyan photons
excite me.I’M EXCITED
Cyan & Bluephotons excite me.
I’M EXCITED
White seen when all three very excitedGray seen when all three less excited
MOE
CURLYCURLY
LARRY
Trichromatic: Color BlindnessRed , Yellow,
Green &Cyan photons
excite me.I’M EXCITED
Cyan & Bluephotons excite
me.Yawn.
MOE
CURLYCURLY
LARRY
Color blindness occurs if the eye is missing one of the three receptors. Other receptors try to compensate but cannot distinguish some colors.
Do I see red or green?
OR
Color Blindness
Classification
Incidence (%)
Males Females
AnomalousTrichromacy
6.3 0.37
Protanomaly(Red-cone weak)
1.3 0.02
Deuteranomaly(Green-cone weak)
5.0 0.35
Tritanomaly(Blue-cone weak)
0.0001 0.0001
Dichromacy 2.4 0.03
Protanopia(Red-cone absent)
1.3 0.02
Deuteranopia(Green-cone absent)
1.2 0.01
Tritanopia(Blue-cone absent)
0.001 0.03
Rod Monochromacy(no cones)
0.00001 0.00001 29 or 70? 21 or 74?
Weakness or absence of one of the three types of cones is the cause of color blindness, leading to a reduced ability to distinguish colors.
Trichromatic: After-Image
First stare at RED
I’M EXCITED!Yawn
.
Yawn.
MOECURLYCURLY LARRY
Me too, but tired.
ME TOO!
I’M
EXCITED!
MOECURLYCURLY LARRY
Then stare at WHITE
Moe and Curly are excited so what color is seen?CYAN (light blue-green)
Negative After-image
Stare, unfocused, at the red cross for 10 seconds then look at white wall
Negative After-image
Cyan
Negative After-image
Stare, unfocused, at the flag for 10 seconds then look at white wall
Negative After-image
Cyan Magenta Yellow
Additive ComplementsLARRY
MOE CURLY
After-image of red is cyan because Larry gets tired so when white light excites all three Stooges, Moe & Curly stronger than Larry.
R
C
CyanCyan = White - Red
Trichromatic: OpponencyYellow &
Redphotons
excite me. I’M
EXCITED
Yellow, Green &Cyan photons
excite me.I’M EXCITED
Oh, Shut The F*@% Up!
Yellow seen when Curly and Larry excited, which can annoy Moe, who then opposes them.
MOE
CURLYCURLY
LARRYShine Red & Green photons (or Yellow photons)
Simultaneous Contrast
Are the two gray bars the same shade of gray?
Yes, the presence of a nearby color affects perception of both hue and value, shifting both towards complement
Does the gray bar look slightly bluish?
Color Vision in the Eye
Three types of cones (color)One type of rod (B/W only)
Additive Color Wheel
R
Y
B G
M
C
Additive Primary ColorsRedGreenBlue
Secondary ColorsYellow (Red+Green)Cyan (Green+Blue)Magenta (Blue+Red)
Human eye has three types of cone cells, sensitive to red, green, and blue
Why Yellow & Orange are Special
Blue
RedGreen
Con
e S
ensi
tivi
ty
Peak sensitivities of green and red cone are close together, so we easily separate colors in this range, probably to spot ripe fruit and …
Wavelength
La Victoria Hot SauceLa Victoria Hot Sauce
Compare the differences going from green to red…
to going from green to blue.
Hue, Saturation, Value
Color wheel is nota single wheel butstack of wheels that range invalue.
HUE
VALUE
SATUR
ATION
Saturation & DistanceLook carefully at the color of the grassy field in the foreground, mid-ground, and background.
The field in the background is less saturated (grayish) and also somewhat bluer.
Atmospheric Perspective
Objects in the distance have a bluish, unsaturated color due to atmospheric scattering of blue light (same as blue sky).
Artists use this effect to suggest distance.
CIE Hue-Saturation Diagram
Eye is not a perfectoptical instrument.
Color “wheel” isactually distortedcone shape.
Rim is full saturation,center is white
LARRY %
CU
RL
Y %
50% Larry50% Curly0% Moe
33% Larry33% Curly33% Moe
Next Lecture Visual Arts @ Nexus
Remember:
Assignment due:
Homework #5 (Visit Exploratorium)