Skip to content
Tom's HikingTom’s Hiking

Lighting and electronics

Flood vs spot beam

Also called wide vs narrow beam, beam pattern

Flood or spot beam: what is the difference?

A flood beam spreads light wide and close for camp tasks and slow ground. A spot beam concentrates it into a narrow cone that reaches further, for seeing ahead at speed. Most trail headlamps mix both, and the mix matters more than the lumen count.

Flood vs spot beam at a glance

Flood
Wide, close, for camp
Spot
Narrow, far, for speed
Most trail lamps
Mix both

What a flood beam is for

A flood beam lights a wide circle a short distance away. It's what you want for cooking, finding things in a tent, and picking your way over rough ground slowly, where peripheral awareness matters more than reach.

What a spot beam is for

A spot beam concentrates the same light into a tight cone that travels much further. It's what lets you see the trail thirty meters ahead while running, and on its own it's disorienting, because everything outside the cone is black and you lose all sense of the ground beside you.

Why good lamps do both

Which is why good trail lamps do both. Some use two separate emitters with independent control, some use a hybrid lens that produces a bright center with a wash around it. Either way, the shape of the beam determines whether the light is useful far more than the total output does, and it's the thing least visible in a spec table. If you can, look at the beam shot photographs brands publish rather than the lumen figure.

What this means when you're choosing

  • Whether flood and spot can be run independently or only together
  • A bright center with a usable wash around it, rather than a hard-edged spot
  • Beam shot images, which tell you more than any number on the box

The common mistake

Choosing one and expecting it to do everything

A pure flood leaves you blind at running pace and a pure spot makes camp tasks a chore, because you light a coin-sized patch of whatever you are holding. What matters is whether the lamp gives you both and lets you pick.

Common questions

Should I get a flood or spot headlamp?

Both, in one lamp. For camp and slow walking a flood is more pleasant; for running or fast descents you need the reach of a spot. Almost every good trail lamp blends the two.

Why does a bright headlamp feel worse in fog?

Because a wide beam reflects off the water droplets straight back at you. A tighter spot angled slightly down cuts through much better, which is one reason mixed-beam lamps are worth having.

Where this comes up

Guides on Tom's Hiking where flood vs spot beam changes which product is right for you.

More in lighting and electronics

Lumens

Lumens measure the total light a headlamp emits in all directions. It's the headline number on every box and it says nothing about where that light goes, so a 400 lumen lamp with a bad beam can be less useful than a 200 lumen one with a good one.

Beam distance

Beam distance is how far a headlamp usefully projects light, quoted in meters. The industry standard measures it to the point where illumination falls to 0.25 lux, roughly the brightness of a full moon, which is dimmer than most people picture.

Regulated output

A regulated headlamp holds a steady brightness as its battery drains, then drops off sharply near the end. An unregulated one fades continuously from the moment you switch it on, so it's dim long before the battery is actually empty.

Reactive lighting

Reactive lighting uses a sensor to measure reflected light and adjusts brightness automatically, dimming when you look at a map and brightening when you look down the trail. It extends battery life and can feel unpredictable at speed.

Red light mode

Red light mode is a dim red setting on a headlamp that lets you see nearby things without spoiling your night vision. Your eyes take 20 to 40 minutes to adapt fully to the dark, and white light undoes that in seconds, while dim red light barely disturbs it.

IP rating

An IP rating states how well a device resists solids and water, under the IEC 60529 standard. The first digit covers dust and the second water, so IPX4 is splash resistant, IPX7 survives brief submersion, and IP67 does both.

Watt-hours (Wh)

Watt-hours measure how much energy a battery stores: voltage multiplied by capacity in amp-hours. Unlike mAh, which is quoted at the cell's own voltage, watt-hours let you compare any two batteries fairly, and they are the unit airlines use to set carry-on limits.

GPX file

A GPX file is the standard open format for storing GPS routes, tracks and waypoints as plain text. It's what you download from a trail site and load onto a watch or phone, and almost every mapping app and GPS device reads it.

Breadcrumb navigation

Breadcrumb navigation draws your loaded route as a line on a blank screen with an arrow for your position, without any underlying map. It tells you whether you're on the route, and nothing about what's around you.

ABC sensor

ABC stands for altimeter, barometer and compass, the three sensors in an outdoor watch. The altimeter and barometer are the same pressure sensor read two ways, and the compass is a magnetometer that gives you a heading when you're standing still.

Exit pupil

Exit pupil is the width of the beam of light a binocular sends to your eye, found by dividing the objective lens size by the magnification. An 8x25 has a 3.1mm exit pupil and an 8x32 has 4mm; the bigger number looks brighter in dim light.

Eye relief

Eye relief is how far behind a binocular's eyepiece your eye can sit and still see the whole field of view, measured in millimeters. Glasses hold your eye farther back, so hikers who wear them need about 15mm or more to avoid a view ringed in black.

ED glass

ED glass, short for extra-low dispersion, is lens glass that bends red, green and blue light by nearly the same amount. In binoculars it cuts the purple and green fringes around dark edges against a bright sky, so the image looks sharper and truer in color.

By Tom · Last reviewed . Back to the glossary