Metamerism Questions and Answers

Answer: A

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason gives the mechanism. A metameric recipe optimised against the reference illuminant can hit those tristimulus values very exactly indeed, while a spectral match limited by the available colourants may leave a small residual difference. The spectral match is nonetheless the better one, because its small difference stays small under every illuminant.

Answer: B

The first two are correct and separate robustness from closeness. The third does not follow, since the two properties are entirely independent. Either can be good while the other is poor. The two are entirely independent.

Answer: C

Printing inks and textile dyes have quite different spectral curves. Shade cards are consequently a poor standard for critical matching. Ink and dye differ spectrally throughout. A dyed standard is preferable for approval.

Answer: D

Both are true and the reason gives the reason, and a dyed standard is preferred. The card serves for communication rather than for final approval. A dyed standard is preferred for approval. Cards serve for communication instead.

Answer: A

Different manufacturers use different colourants for the same nominal shade. The room may be lit by daylight by day and by lamps in the evening. Different suppliers use different colourants. Day and evening lighting differ markedly.

Answer: B

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: different suppliers use different colourants, which is exactly the condition for metamerism, and a room lit by daylight in the morning and lamps in the evening exposes the failure without anyone looking for it. Statement 3 is wrong - measurement detects and quantifies metamerism but cannot remove it, since the cause lies in the colourants.

Answer: C

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason gives the mechanism. The spectral difference exists in the samples, and no amount of measuring changes it. Measurement’s contribution is to reveal the problem early, before production, so that the recipe can be reformulated with different colourants - which is the only thing that does remove it.

Answer: D

A spectral tolerance constrains the curve shape rather than the integrals alone. It is demanding but gives the most durable match. Curve shape rather than integrals is constrained. It is demanding but the most durable.

Answer: A

Correct answer: reducing the number of samples measured per batch

The three effective controls all attack the spectral difference or expose it: requiring the standard’s colourants prevents it, multi-illuminant tolerances limit it, and a spectral tolerance constrains the curve itself. Measuring fewer samples only reduces the chance of noticing a problem that is already there.

Answer: B

Correct answer: camouflage designed to match under one condition only

Camouflage is the standard example of metamerism used deliberately: a pattern is formulated to match foliage under the conditions in which it must not be seen. The exploitation is precisely of a match that need not hold universally - and the same reasoning warns that it may fail under a sensor the designer did not consider.