Color Vision #3

Question 1

Luminous efficiency. Peak is at ___ for photopic conditions

Answer 1

555nm

Question 2

Best hue/wavelength discrimination is at ___nm and ___ nm.

Answer 2

495nm and 590nm. Only need 1nm change in wavelength in order to detect a change in hue. Other wavelengths require more change in order to detect new hue.

X axis is wavelength, Y axis is change in wavelength

Question 3

___ is the least saturated spectral color and the one for which saturation discrimination is poorest

Answer 3

Yellow. 570nm.
Means that you have to add the most amount of yellow to white light in order for a person to recognize a color change.

X is wavelength
Y is colorimetric purity
Keep in mind colorimetric purity is the physical form of saturation, which is the perceptual form.

Question 4

Bezold Bruck Phenomenon

Answer 4

Changing the brightness/value also changes the hue for most wavelengths. AKA hue/wavelength depends on brightness intensity.

EXCEPTION: 3 invariant wavelengths that do not change wavelength when brightness changes.

Question 5

Bezold Bruck Graph

Answer 5

X axis is wavelength
Y Axis is log luminance intensity.

Most wavelengths will shift as intensity changes on the Y axis except the 3 invariant wavelengths. Those wavelengths will be represented as a straight line, indicating that the wavelength remains the same although intensity is changing.

Question 6

How do rainbows work

Answer 6

Different wavelengths reflected/refracted in water droplets.

Question 7

Everyday phenom of colors

Answer 7

Rainbow
Moonbow
Looking at moon from earth- will see blue because light is scattering caused by earths atmosphere in the way of your view.
Water has intrinsic blueness due to vibrations
Sunrise and sunset. Vibrations cause energy to be high enough to be in red end of spectrum. Light rays travel further too.
Auroras- charged particles from the sun interact with magnetic field and collide, releasing energy.