Principles of Color Science Flashcards
What three things affect the interaction of illumination between the object and the human visual system
gloss
translucency
color
This is the amount of light reflected at the surface of a material, with consideration also of the dispersion or scattering of the reflected light from the specular angle of reflection
gloss
True or False
Although instruments are available to measure gloss, most instruments do not precisely cover the entire range of possible gloss value
True
Visual assessment of gloss is recommended for clinical evaluation via knowing these three things
know the shape of the illuminant
assess the quantity of reflected light
assess the quality of reflected light
What are the three components of color
illuminant
object
observer (receives and interprets)
This quality is when light cannot pass through the material, the material masks any underlying color
opaque
This quality is when light, and therefore color pass through the material but it partly absorbed, scattered, or both
translucent
This quality is when light and color pass through the material unaltered
transparent
The illuminant, the object, and the light entering the eye are each this
spectral, comprising energy at every visible wavelength
What is the visible light spectrum
380nm-780nm above UV and below infrared
What is CIE lightness (L*) or Munsell Value
taking a color, red for example, and making it lighter (more white) or darker
Although light entering the eye is spectral, the 3 different types of cones in the eye simplify this spectrum unto what
3 aspects or the 3 dimensions of color; value, chroma, hue
What are the two dimensions os chromaticity
chroma and hue
What are the variations in Munsell hue
differences like between red - blue - yellow - green - purple - blue/green - red/purple - etc.
What are the variations in Munsell chroma
increasing the intensity of the color, like red, red → more red → super red, etc.
What is the perceptibility threshold
“scientifically there is a color difference, but cannot physically see it”
What is the value of color difference when comparing two colors
ΔE is approximately one is perceivable, if the difference between two colors is ≥1, then differences are noted
For tooth colors, what is the limit of perceptibility
2 CIELAB units
In dentistry, a CIELAB color difference of less than what may generally be considered as acceptable
~3.5
What are the specifications of illuminants involving color temperature
if you heat things up, the color can change from red → yellow → white → blue
What is the color of the temperature 1,800K
red-orange
What is the color of the temperature 3,000K
yellow
What is the color of the temperature 5,555K
white; balanced white light
What is the color of the temperature 25,000K
bluish white
