Spread beam

Also called spread pattern, wide driving beam, spread lens, peripheral beam, wide cornering

A spread beam is a wide off-road driving pattern shaped to push light sideways along the edges of the trail, and what separates it from a flood is where the light is aimed rather than how wide it is: a spread reaches out along the trail ahead, a flood fills the near ground around the vehicle.

What is a spread beam?

KC HiLiTES defines it as a bright, wide beam that prioritizes peripheral visibility and clarity for off-road driving. Set that beside the same guide's flood, which is typically used as work, scene, camp or back-up lights to see a broader area with a shorter distance, and the split is clear enough: one maker, two wide patterns, sorted by whether the vehicle is moving.

The numbers show it is a real distinction and not a marketing one. KC's FLEX ERA 1 is a single 2,430 lumen pod sold with three lenses, and the maker's table gives 4,510 candela on flood, 16,200 on spread and 31,000 on spot. Spread has three and a half times the flood's peak intensity and about half the spot's. It is wide, but it is not evenly wide: a spread still concentrates light, into a broad horizontal band rather than into a cone. A flood spends its light in every direction it can reach and keeps almost none.

Where makers blur it

Inside a single catalogue, to begin with. KC's guide lists back-up lights among the uses of a flood, and KC's two FLEX ERA 1 backup kits, the standard and the flush mount, are sold in spread only. The boundary moves between the guide and the shelf.

Between makers it moves further. Baja Designs has no spread at all. Its wide driving pattern is Wide Cornering, a 42 degree flattened horizontal beam the company says reduces blind spots and improves peripheral visibility, and its even wide pattern is Work/Scene, described for construction sites, camp setups and pit areas. Two companies, four names, and the same two underlying ideas.

Flat and horizontal for moving. Even and hemispherical for standing still. Every maker sells both. No two call them the same thing.

What a spread is for

Seeing the sides of the trail while you drive it: the corner you are turning into before the headlights swing round to it, the ditch edge, the animal about to step out of the brush rather than the one already standing in front of you. It is the complement to a spot rather than a substitute, and a build running one narrow lamp and one wide one is running this pair.

It belongs low, for the same reason every wide pattern does. A broad beam lights a large volume of air close to the vehicle, and that volume sits in your sightline if the lamp sits at your eye level. Baja Designs keeps its wide patterns in the two lowest zones and recommends eighty percent of a lighting package stays below the hood line.