Beam Spread

The Beam Spread report calculates beam width values for the selected photometries. It is intended for luminaires where the useful light output can be described by one or more angular spread measurements.

Report Values

The report evaluates the angular width of the distribution at common relative intensity levels. Typical beam metrics include full width at half maximum and wider field-angle values. Narrow values indicate a concentrated beam; wide values indicate a broad distribution.

Reading The Diagram

Use the diagram to compare spread in the main photometric planes. If the distribution is asymmetric, the reported values can differ by plane. Review both the numeric values and the plotted shape before assigning a beam category.

Practical Use

Beam spread is useful for spot, flood, high-bay, and accent distributions. For general area or roadway luminaires, combine this report with zonal lumen, LCS, or roadway reports for a more complete assessment.