SI unit of measurement

Definition of Lumen

A lumen is a standard unit that measures the amount of visible light emitted by a light source. It’s the most basic measure of light on which all other light measurements are based, including lux, foot-candle, and candela.

‚Äčdiagram of lumen, candela, and lux

Basically, a lumen is a unit of brightness, and the more lumens a light fixture has the brighter it is. It’ll impact your choice of light fixture since higher lumens are typically used for high precision tasks or night visibility.

For example, one of the brightest lights Apex Lighting carries, at 11,000 lumens the Bluefin LED Great White 48 Color Changing, perfect for night fishing and accessorizing your boat.

On the other end is the LED Anywhere Light, which at 136 lumens is fantastic as a courtesy light or for a boat’s walkaround cuddy.

The lumens emitted by a light source can be affected by several factors:

  • Type of bulb: A high-quality LED chip with a good LED driver will emit more lumens than a low-quality LED chip with a poor driver.
  • Light fixture design: A well-designed fixture will have reflectors and lenses that optimize light distribution, resulting in more lumens being emitted.
  • Condition of the bulb: It’s important to replace bulbs that are nearing the end of their lifespan as they become less efficient and emit fewer lumens. Be sure to go with high quality LED bulbs.
  • Distance from the light source: A light source that is farther away will appear dimmer than one that is closer, therefore having a lower perceived brightness
  • Angle of light output: A narrow beam angle will produce a more focused, intense beam of light, while a wider beam angle will produce more diffused light.

Example of Lumen in a Sentence

"The LED light bulb produces 2,000 lumens, making it a bright and energy-efficient option for deck flood lights."

Synonyms: brightness

Related Terms for Lumen