Metameric Matching, Grossman & CIE Chromaticity

Question 1

What is a metamer and give an example

Do the colors look alike?, do they have different spectral reflectance curves, Example related to paint

Answer 1

• 2 colors that appear to look alike with different illuminations but have a different spectral reflectance curves
• Example is paint color selection

Question 2

What is the definition of an isomer?

Answer 2

• Two colors containing identical wavelengths

Question 3

What is Grossman’s additive law?

Relates to metameric match

Answer 3

• Equal radiation added to both sides of a metameric color match will still match

Question 4

What is Grossman’s scalar law?

Relates to metameric match and proportions

Answer 4

• if both sides of a metameric match are changed by the same proportion they still match

Question 5

What is Grossman’s associative law?

interchangable colors

Answer 5

• If A is a metameric match to B, then A and B can be used interchangably in color matching

Question 6

What is significant about the inner triangle of the CIE chromaticity diagram?

(Is the light visible?)

Answer 6

• Inclusive of all colors seen by the human eye

Question 7

What is significant about the spectral locus of the CIE chromaticity diagram?

(where along the inner triangle is it located and what is significant about the colors at that area?)

Answer 7

• periphery of the graph where colors are the purest and most saturated

Question 8

What is true about CIE Chromaticity Diagrams?

A) Allows for Coloring Mixing
B) Can determine dominiant wavelength of a color mix
C) Can calculated Excitation Purity [=a/(a+b)]
D) All of the above

Answer 8

D) All of the above

Question 9

What is the definition of complementary colors and complementary wavelengths on the CIE Chromaticity Diagram?

Answer 9

• Complementary Colors: any two colors on the opposing side of white
• Complementary wavelengths: wavelengths on the spectral locus associated with the complementary colors

Question 10

What are three factors that influence how colors are percieved of a surface?

(Light Sources, Reflection, which part of the retina transmits color?)

Answer 10

1) Light sources
2) Spectral reflectance properties
3) Stimulation of 3 types of cones in retina