Design Guide

Beam Angle Guide For Retail And Display Spotlighting

Choosing between 24, 36, 45 and 60 degree beams, and calculating the pool of light you will get.

What Beam Angle Describes

Beam angle is the cone within which the lamp delivers at least half its peak intensity. Outside that cone there is still light, but it falls away quickly.

A narrow beam concentrates the same lumens into a smaller area, so it produces a brighter, tighter pool. It is not more light; it is the same light placed more deliberately.

Calculating The Pool Of Light

A workable approximation: the diameter of the beam at a given distance is roughly the distance multiplied by a factor that depends on the angle. For a 24 degree beam the factor is about 0.42, for 36 degrees about 0.65, for 45 degrees about 0.83 and for 60 degrees about 1.15.

So a 24 degree lamp three metres above a table produces a pool of roughly 1.3 metres across, while a 60 degree lamp at the same height produces roughly 3.5 metres. That difference is the entire design.

Matching Angle To Task

Narrow beams of around 24 to 36 degrees are for accenting individual objects - a mannequin, a display case, a single product on a plinth.

Around 45 degrees is a general display angle, suited to a shelf run or a table of goods.

Around 60 degrees washes a wall or covers a broad area, and is closer to general lighting than to accenting.

We hold 24 to 36, 45 and 60 degree versions of the GU10 5W lamp as separate part numbers, which is the only way to make sure the right angle arrives on site.

Contrast Ratio Is The Point

Accent lighting works by contrast. A display lit at roughly three times the surrounding level reads as highlighted; at ten times it reads as dramatic.

If the general lighting in the space is already bright, accent lighting has to be brighter still or it disappears. Sometimes the correct answer is to reduce the ambient level rather than increase the accent.

Common Mistakes

Using one beam angle across a whole store, which produces either scalloped walls or a flat, undifferentiated floor.

Mounting narrow beams too high, so the pool spreads and the effect is lost.

Mixing beam angles within one run of track without intent, which reads as an error rather than as a design.