Beam angle

The beam angle is the term used to describe the lighting distribution in 360 degrees of a certain light fixture. The beam angle of a light source is the angle measured between the central axis of the source to the boundary  where the lighting intensity decreases to 50% (Also see full-width at half maximum)

Beam angles can be e.g. narrow, medium, wide, asymmetric in their distribution. Knowing the beam angle of a fixture is a crucial parameter when designing lighting.

Tip from a lighting designer

At Studio De Schutter we carry out  beam angle studies to identify the correct luminaire placement or to assess if a certain beam spread fits the situation. We always check  that the beam angle is neither too flat nor too parallel to an object. Optimal positioning and selection of beam angles can avoid mistakes like unwanted glare, too sharp or too soft light edges.