from the spectrum lab: light waves with different wavelengths appear as different colors. short...
TRANSCRIPT
From the spectrum lab:• Light waves with different
wavelengths appear as different colors.• Short waves are blue/purple.• Long waves are red.
More than just wavelength...• There is no “brown” or “pink”
wavelength of light.• Color is a PERCEPTION, not a
reality. That is:–Color only exists in your mind.
What is going on?• You cannot trust your brain.• Your perception of the world is
different than the actual world.
Real spectra...• Objects emit/reflect light with
different sets of wavelengths.–Bright in areas, dark in others:
Spectra and the eye• Eyes can’t see all that detail.• Can’t measure the amount of
light of every wavelength.• They check THREE PARTS of
the spectrum...– red, green, and blue parts
Rods and Cones• Four types of light-detecting cell
in your eye:– Rods: very sensitive to all light– Cones: less sensitive, tuned to
certain colors (Red, Green, Blue)
Primary colors• 3 cones → 3 primary colors• Computers and TVs display
colors with an “RGB” system for Red, Green, and Blue.
Primary colors• “Red, yellow, blue” are a BAD
CHOICE for primary colors.• Even in pigments! They can’t
make a full color gamut (range).• Cyan, Magenta, and Yellow form
the CMYK system for pigment/ink.
Different numbers of cones• Some humans only have 2 types of
cone! They are color deficient or color blind. (About 1% of men.)• Some women may have 4 cones!!
They’d see differences in color that nobody else does! Tetrachromacy in humans is a new, uncertain discovery.
Cones in other animals•Most mammals have 2 types.–Dogs don’t see in black & white!–It’s just a limited set of colors.
• Higher primates have 3 types.• Some birds, reptiles, and insects
have 4 or even 5!