28. You have two samples of cloth, one that looks blue (B) and one that looks ye

Question

28. You have two samples of cloth, one that looks blue (B) and one that looks yellowish- red (Y-R). Illuminated by a lightbulb whose CRI is 100, the two samples appear equal in brightness. Now you change lightbulbs, illuminating the same two samples with a bulb whose CRI is much lower, say 50. Which of the following will be true? a. B will look brighter than Y-R b. Y-R will look brighter than B C. B will look the same brightness as Y-R d. Y-R will become near invisible e. None of the above is true

Explanation / Answer

28] CRI is the Color Rendering Index of a light source. It is a scale which quantifies how accurate a given light source is in reproducing the object's colors (or in other words, rendering the colors from the object) when compared to a standardized light source. Its value varies from 0 to 100 with 100 being for an ideal black body or daylight.

Higher the CRI of a light source, better is the color discrimination capability of the light hence better color rendering.

So, if the CRI of the above lightbulb is changed from 100 to 50, the brightness of the colors will not change but the colors will almost start to look identical. This is because if the light source has a different spectral composition (does not contain the same wavelengths), the object will not reflect the desired color which it would in sunlight and hence it would not appear to have the same color as under sunlight.

hence the answer is [d] as the red-yellow cloth will start to look orangish and smear out in the background.

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.