What is Lux?

Fengxiang Li
2021-11-03T11:00:00-07:00

If you have LED lights or are considering it, you must have heard all the advice about how vital it is to have adequate lux levels. But what is lux, and what does it even mean?
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Image source: Green Business Light UK

If you have LED lights or are considering it, you must have heard all the advice about how vital it is to have adequate lux levels. But what is lux, and what does it even mean?

According to Wikipedia, lux (lx) is an SI unit for illuminance. It measures luminous flux per unit area. Lux is equal to one lumen per square meter. In simpler terms, lux is a measure of how well a particular location is illuminated.

In this article, we shall discuss:

What is lux in lighting

What is lux vs. Lumens

What is a lux meter?

What is lux rating?

What is lux setting on a motion sensor?

What is Lux in Lighting

Below is a great example to show you what lux in lighting is:

Get into your dining room and turn on all the lights. Observe the surface of your dining table. Let’s say you have 460 lux in total measured by a lux meter. If you turn off one of the lighting fixtures, the surface of your table will automatically get darker, and you can’t see as well. If you measure again using a lux meter, you might have maybe 280 lux now.

Lux is all about the amount of light you can feel around you. If the light around you is bright, then you have higher lux levels. If it’s darker, lux levels are lower.

What is Lux vs. Lumens

Both lux and lumens are related to brightness, but they measure different things.

The Difference between Lux vs. Lumens

Lux measures illuminance (the amount of light falling on a surface). On the other hand, lumens are the amount of luminous flux (the amount of light emitted in different directions). The direction of the light source is essential in lux irrespective of how many light sources there are and the color of the surface where the light shines.

What is a Lux Meter?

A lux meter is a device used to measure brightness. It’s also called a light meter. A lux meter measures the intensity of brightness as the human eye perceives it. This is not the same measurement method used to measure light energy reflected or produced from a light source or object.

LED lighting surveyors use lux meters to measure lux. Once they get into a room, they will use a lux meter to take readings from different points. They do this so they can evaluate how different lux levels are from separate locations. They can then use lux software to show you a ‘before and after’ of your current lighting and how it would be once you install LED lighting.

What is Lux Rating

Lux rating measures the amount of light visible that a camera can see while still offering a clear picture. If a camera has lower lux, it will need much less light to provide a good shot.

What is Lux Setting on a Motion Sensor

Lux controls the night and day setting of your motion sensor and will have an image of the sun and moon. When you move it towards the sun, it will come on when it’s much lighter and when you move it towards the moon, it will only come on when it’s dark.