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subjective brightness

[5.9.10.1] The subjective attribute of any light sensation giving rise to the percept of luminous magnitude, including the whole scale of qualities of being bright, light, brilliant, dim, or dark. (See sensation of a perceived color.)

Note: The term brightness often is used when referring to the measurable luminance. While the context usually makes it clear as to which meaning is intended, the preferable term for the photometric quantity is luminance, thus reserving brightness for the subjective sensation. (See luminance.)

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