## Luminance Calibration

ElumTools has the capability to assign an arbitrary, self-emitting Luminance and color to any material. This is typically useful when attempting to simulate an area or linear source with uniform surface luminance such as an LED strip, OLED panel, or other decorative source (neon, cold-cathode). The output is considered in the computation of overall environmental exitance and subsequent illuminance calculations.

 The Luminance value in cd/m2 indicates the absolute diffuse Luminance of the material specified as a value between 1 and 30000. Think of this as the absolute ‘brightness’ of the surface.   Luminance can be specified in terms of any of the following units: cd/m2 (default), Lumens/ft2, Lumens/m2, Lumens/ft, Lumens/m. For the specification of luminance per linear distance, a nominal width is assumed as shown in the table below. If the width of the luminous element differs from the nominal width, the width can be changed in the dialog. Unit Width Conversion Example: Lumen / Ft2 Included Multiply by 10.76 (ft2 to m2 conversion); divide by Pi (3.14159265) 100 Lumen / Ft2 =100 * 10.76 / 3.14159265   = 342.451 Cd / m2 Lumen / Meter2 Included Multiply by 10.76 (ft2 to m2 conversion); divide by Pi (3.14159265) 100 Lumen / Meter2 = 100 / 3.14159265   = 31.831 Cd / m2 Lumen / Linear Ft 0.042 Ft (may be changed) Multiply by 10.76 (ft2 to m2 conversion); divide by (Pi (3.14159265) multiplied by calculated Square footage) 100 Lumen / Linear Ft = 100 * 10.76 / (3.14159265* 0.042 Sq Ft) = 8153.584 Cd / m2 Lumen / Linear Meter 0.015 Meter (may be changed) Multiply by 10.76 (ft2 to m2 conversion); divide by (Pi (3.14159265) multiplied by calculated Square meterage) 100 Lumen / Linear Meter = 100 / (3.14159265* 0.015 Sq M) = 2122.066 Cd / m2