CLC CLC Photometry & Color Science 2

Question 1

The MacAdam ellipse is used in lighting to define acceptable limits of what characteristic?

Accepted Answer

Color consistency (chromaticity variation) between lamps

Answer

MacAdam ellipses define the chromaticity region within which two light sources appear identical in color to the human eye.

Question 2

Illuminance is measured in foot-candles (fc) in the US customary system; what is the SI equivalent unit?

Accepted Answer

Lux (lx)

Answer

Lux is the SI unit of illuminance; 1 foot-candle equals approximately 10.76 lux.

Question 3

Which phenomenon causes colors to appear differently under a light source with a narrow spectral power distribution compared to broadband white light?

Accepted Answer

Metamerism

Answer

Metamerism occurs when two colors appear to match under one illuminant but differ under another due to differences in spectral reflectance.

Question 4

The TM-30 system improves upon CRI by adding which metric to assess the gamut (saturation) of rendered colors?

Accepted Answer

Rg (Gamut Index) alongside Rf

Answer

TM-30 uses both Rf (fidelity) and Rg (gamut index) to give a more complete picture of color rendering quality than CRI alone.

Question 5

In photometry, a candela (cd) measures which quantity?

Accepted Answer

Luminous intensity in a specific direction

Answer

The candela is the SI unit of luminous intensity, representing the power of light emitted in a specific direction per unit solid angle.

(CLC) Certified Lighting Consultant Practice Test

(CLC) Certified Lighting Consultant Practice Test

CLC CLC Photometry & Color Science 2