Fundamentals 01
Beam Angles
The angle of a fixture's cone of light — the single most important optical choice in accent lighting.
The beam angle is the angle at which the light intensity falls to 50% of the centre value. Narrow beams (8°–15°) concentrate light on a small area with high intensity; wide beams (36°–60°) spread it over a broader field with lower intensity.
The correct beam angle is a function of throw distance and target size. Doubling the throw doubles the diameter of the illuminated field for a given angle — geometry, nothing more.
Beam angle is not intensity. A wider beam at the same wattage produces less illuminance at the centre, not more, because the same lumens spread across a larger area.