physics

• spectral colors: correspond to a specific wavelengths in a rainbow
• white light is made up of all the spectral colours
• perceived colors- combinations of colors that cannot be represented in the rainbow
• Primary additive colors: Red Green Blue, all combined is equal to white light
• Primary Subtractive colors- Cyan, Yellow, Magenta, Key-black
• what are color complements: two colors when added give white
• intensity distribution- A graph of intensity vs wavelength, a spectrum
• metameter- a color which can be expressed as more than one combination of colors.
• 3 things our eyes are sensitive to- Hue, Saturation, and Lightness.
• #9 study guide
• Dichroic filters have a thin film on glass which transmits the colors we want, and reflects away colors we don't.
• Question 10
• Transmission curves- describe the efficiency with which different wavelengths get through a filter.
• reflection curves- describe the efficiency at which different colors get reflected by a surface such as printed paper.
• Question 12
• if you repeatedly mix a Dye, you multiply its reflection curve by itself at each wavelength
• Dyes absorb colors we don't want and reflect the ones we do, like ink.
• halftones- mixtures of close together dots whose color and size create continuous distribution of color to the eye. example News paper print
• protanopia-red cone missing
• deuteranopia- Green cone missing
• Trichromacy- blue cone missing
• Rod Monochromaticity- can only see with their rods so they are sensitive to light
• Opponent Processing Theory- the theory that we perceive colors in mutually exclusive pairs, such as yellow-blue, green-red, black-white.
• Chromatic lateral inhibition - color on the side, how our vision suppresses perception of antagonistic colors when they are seen side by side
• Color Constancy - the ability of our vision to maintain the same perceived relative color contrast between objects no matter the light level.
• lightness constancy - suggests relative lightness of an object perceived as consistent under different intensity of light
• diffraction - an effect produced by how wavelets from differs part of the same wave front combine
• interference - the effect from the multiple independent wave fronts from distinct light sources.
• #2 b
• Huygens principle - every point on a wavefront is in itself the source of spherical wavelets which spread out in the forward direction at the speed of light.
• wavelet - a wave-like oscillation with an amplitude that begins at zero, increases or decreases and then returns to zero one or more times.
• Shadows- at places where wavefronts are blocked by an obstacle, some wavelets cannot be connected together, causing distortion of the wave front at the next steps in time and leading to blocked areas where no light arrives along with smeared edges to those shadows.
• Phase of a wave - phase is how out of set two wave patterns are, and is measure in units of length, same as wavelength.
• coherent light - wave sources maintain either a constant or a consistent relative phase between the waves.
• Change the phase of a wave- hard reflection, knocks one wave out of phase by 180 relative to another, and physical offset between two sources