Beam angle defines the spread of light from a luminaire, measured as the angle between two points where luminous intensity falls to 50% of the center beam maximum (IEC 62471). Narrow beam (10–30°): accent, track lighting, art highlighting. Medium beam (30–60°): task lighting, downlights. Wide beam (60–120°): general area lighting, floodlights, high bays. Beam angle directly affects lux levels and spacing criteria—narrower beams require closer fixture spacing. The field angle (10% intensity threshold) is also specified for complete photometric data.