Thread Subject: Re: 2.1-B -LuminanceContrastfor Legends

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From: Robert_Nerhood@Dell.com
Date: Tue, Oct 16 2007 11:50 AM

L is a measured value of the light reflected from the keyboard from a
light source. L = luminance which is in candelas/meter squared. In
many environments it's still refered to as NITS (which is a lot easier
to say than cd/m2).



So to measure luminance contrast a light source is projected onto the
surface. A photometer is set up and you measure the luminance coming
from the legend and the luminance coming from the background. Those
values are then plugged into the equation provided.



From: = EMAIL ADDRESS REMOVED =
[mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Gregg
Vanderheiden
Sent: Tuesday, October 16, 2007 12:41 PM
To: 'TEITAC desktop/portable (hardware) subcommittee'
Subject: Re: [teitac-hardware] [teitac-committee] 2.1-B
-LuminanceContrastfor Legends



L is measured in cd/m2. But what is the value of it?





L1 is the higher luminance

L2 is the lesser



But what is L? what value would I plug in for an evaluation.




Gregg
-- ------------------------------
Gregg C Vanderheiden Ph.D.

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