Beam angle is useful for comparing distributions, but it does not describe every detail of a lighting pattern. Real beams can contain central peaks, gradual falloff, asymmetric spread, secondary light, and effects created by the source, lens, reflector, and diffuser.
Beam Spread
Narrow and Wide Distributions
A narrower beam concentrates a greater portion of the light into a smaller angular region. A wider distribution spreads light over a larger area.
Neither is automatically better. The useful choice depends on the size of the target, mounting distance, fixture spacing, and required illuminance.
Working Distance
A fixed angular distribution covers a larger area as the distance between the fixture and target increases.
This relationship is one reason beam selection should be based on the real installation geometry rather than fixture specifications alone.
Secondary Optics
LED packages have their own native distribution. Secondary lenses and reflectors can collect portions of that light and redirect it into narrower, wider, elliptical, linear, or specialized patterns.
Uniformity
Two fixtures can illuminate the same overall area while producing very different intensity patterns. One may concentrate light near the center while another distributes output more evenly.
Uniformity can be particularly important across workstations, inspection areas, and continuous machine surfaces.
Fixture Arrays
Large areas are often illuminated by several fixtures whose distributions overlap. Fixture spacing, beam spread, mounting height, orientation, and surrounding surfaces determine whether those overlaps produce smooth coverage or visible bright and dark zones.
Inspection
Inspection lighting is often designed around the way a target reflects light toward a camera rather than around general human illumination.
Ring lights, low-angle illumination, backlighting, diffuse lighting, and directional lighting can reveal different surface features.
Inspection Lighting →Selection