upcoming classes thursday, nov. 29 th making color (visual arts @ nexus) assignment due: * homework...

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)