By Ben Ellison
Is there a common standard for measuring screen brightness? A.C., via e-mail
Luminance, whose definition is just too complicated to attempt here, is related to perceived brightness, and it can usually be measured. Units of luminance are expressed as candela per square meter (cd/m2) or, strangely, nits (from the Latin nitere, “to shine”). That’s the sort of “light intensity” measurement that you may be seeing in the display brochures (and in this month’s new products), which probably prompted your question. My experience is that screens with nit ratings of more than 1,000, look pretty bright, but screens with lower ratings do not necessarily seem less bright, definitely not proportionally so. I’m told that high nit ratings are achieved with intense backlighting but that factors like antiglare coatings, rich colors, and high contrast are also important to viewability, which echoes Halsted’s lengthy full analysis. Plus there are screen-brightening techniques like transflectivity that cannot even be conventionally rated for luminance.
Above all, keep in mind that for you, as a human with “nonlinear and complex” perceptions (isn’t it heartening that we can’t be quantified?), display performance is not fully measurable. Try to preview a screen in all the light conditions in which you’ll use it before you commit.
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This article originally appeared in the October 2004 issue of Power & Motoryacht magazine.