Lumens vs Candela Weapon light beams side by side

Lumens are all the light a weapon light emits, counted in every direction. Candela is the intensity of the beam at its brightest point, the center of the hot spot, and it does not change with distance. What you see on a target is lux, lumens per square meter of target, and the center of the beam lands candela divided by distance squared: 100,000 candela puts 1,000 lux on a target 10 meters away and 250 lux at 20 meters.

Two lights with the same lumens can throw very differently. A reflector or lens that squeezes the output into a tight hot spot raises candela without adding a lumen; one that spreads it wide lowers candela and lights more of the room. That trade is what the comparison above shows, pane by pane, with every light in the same scene and the same camera exposure.

Divide candela by the distance in meters squared. A SureFire X300U-A at 11,300 candela lands about 1,500 lux on a target at 3 yards, 135 lux at 10 yards and 5.4 lux at 50 yards. Double the distance and the light on the target drops to a quarter, which is why a light that looks blinding across a room can barely show a target at 50 yards.

The table above reads each light at every target distance in the scene, and the highlighted column follows the distance you pick. Run the same lights through a room clearing in the combat course simulator, where the weapon light rides the rifle in a dark shoot house.

ANSI beam distance is where the center of the beam falls to 0.25 lux, roughly a full moon on a clear night. It is computed from candela, not measured downrange: the square root of candela divided by 0.25, or twice the square root of candela in meters. A 20,000 candela light rates 283 meters and a 100,000 candela light 632 meters, so five times the candela buys a little over twice the distance.

The comparison computes beam distance from each light's published candela and checks it against the maker's published beam distance where the catalog carries one. Every published figure in the catalog agrees with its candela to within 3%, the rounding makers apply.

Divide lumens by candela and you get how much of a light's output goes wide instead of forward. The weapon lights in our catalog run from 6.8 lumens per 1,000 candela on the SureFire M340DFT-PRO, a turbo head built to throw, to 113 on the Streamlight ProTac 2.0 Rail Mount and 175 on the SureFire XSC, the floodiest pistol light in the catalog. A high number means a wide, bright spill; a low one means a tight hot spot that reaches.

The spill readings and the beam profile chart use one generic beam shape for every light, a hot spot plus an even spill, scaled by each light's published lumens and candela. Makers do not publish their beam profiles, so the shape is a teaching model; the center reading at the aim point is exact. Pick lights for your rifle in the best AR-15 weapon lights guide or for a handgun in the best pistol lights guide.

Indoors, distances are short, so even modest candela lands a lot of light on the target: at 7 yards a 100,000 candela REIN 3.0 lands about 2,400 lux and an 11,300 candela X300U-A about 280 lux. What separates lights in a house is the spill: how much of the hallway, the doorways and the corners each one lights. Switch the scene to Hallway to compare that.

Outdoors, candela is the number that matters. At 50 yards the same pair lands 48 and 5.4 lux, and the gap shows in the Yard scene as a target you can read against one you can only find. If the rifle may be used past the house, shop candela first, then lumens. The Streamlight vs Cloud Defensive vs SureFire comparison and the lightest rifle weapon lights ranking weigh output against runtime, weight and mounting.

Each pane renders the same 3D scene from the same eye with only its own light on, a hot spot and a spill from the light's head on the rifle, in candela with real inverse-square falloff, through one camera exposure shared by every pane. That keeps the panes honest against each other: a pane that looks dimmer is dimmer. The hallway uses a darker exposure than the yard, the way your eyes stop down in a lit room. Your screen cannot show the eye's night adaptation, so judge the panes against each other, not against what you see in the dark.

Every light here publishes both lumens and candela. Lights that publish only one, and lights with separate flood and spot beams, are left out rather than guessed. Put a light on your build in the rifle configurator.