Remember back (not too far back) when we spilt the science behind how we created LEDs with the world’s highest light quality? Look, we’d forgive you if you’ve forgotten. This year has been a wild ride since Netflix began cracking down on shared passwords.
To recap, we covered CCT, CRI, TM-30, and importantly, lux. And, today, we’re deep diving into all things lux, including walking you through Brightgreen.com’s nifty new lux meter that’ll make choosing lux levels easy-peasy.
And in case you have forgotten, lux is a unit of illuminance and not just the word millennials would use to describe getting chauffeured in a Lamborghini while wearing Louboutins, and simultaneously getting a deep tissue massage. Although, that too, is indeed very lux.
What is Lux, Anyway?
Ever wondered how we measure the brightness of light in our spaces? It’s all about lux, babyyy.
Lux is the unit of illuminance, measuring luminous flux per unit area. Simply put, lux measures the amount of light falling on a surface. It’s a key concept in photometry, the science of measuring visible light, and is used to quantify the intensity of light as distinguished by the human eye.
Wait. Isn’t There Something Called Lumens, too?
Lux and lumens are often confused for each other, but they measure different aspects of light.
Here’s the shortcut: Lux measures how much light you have on a surface, while lumens tell you the total light emitted by a source (luminous flux). It’s like the difference between the amount of paint on a canvas (lux) and the amount in the paint can (lumens).
The Numbers Game: Making Sense of Lux
One lux is equivalent to one lumen per square metre. This implies that the same amount of light, measured in lumens, will produce different levels of illuminance depending on the area over which it is spread.
Let’s use a simple analogy. Think of light as water (or, perhaps, kombucha—if you’re into that) and lux as a measure of how much water (or kombucha) covers a surface. This means if you have the same amount of light (lumens), the area it covers determines how ‘bright’ it feels. And so, 1000 lumens will appear starkly different in a small space compared to a very vast space.
Brightgreen’s Lux Level Guide
When it comes to picking lux levels, architects and lighting designers use a nuanced approach, considering both the design of the space as well as the selection of light sources (eg, downlights, surface lights, pendant lights, and more).
It’s a mixture of art and science, but established lux-level recommendations provide a helpful starting point from which to iterate. Here’s our official cheat sheet on how to become a certified lux-level whisperer (read: lux-level recommendations):
Domestic Design Standards
As you know, many countries have codes and standards that regulate their domestic design industry, including lux requirements for lighting design. When working out your lux requirements, you’ll need to consult the standards in your country alongside our recommended lux levels.
In Australia, the relevant standard is AS/NZS1680. Here’s a snippet:
Brightgreen’s Lux Meter Design Tool: Making Lux Calculus Easy Peasy
Remember, lux is about the amount of light falling on a surface. So, not only will lux levels change based on the lumens of a fixture, they can shift due to beam angles, a luminaire’s distance from the surface, and the number of LEDs.
In short, a room’s geometry will dramatically change the lux levels achieved by a light source. For the nerds, lux levels in a space can be calculated using a formula that accounts for the lumens value from the light source, the utilisation factor (reflecting room characteristics), and the maintenance factor (allowing for light depreciation over time).
Now, we’ve made these calculations easier by incorporating a lux meter tool directly on our website. By clicking the toggle and playing with the ceiling height slider, you can get updated lux information for a specific product and ceiling height.
Living the Lux Life
It’s official. You’ve graduated from Brightgreen’s School of Lighting Whisperers, and are now officially an expert in all things lux. Unfortunately, we’re unable to provide you with a testamur, but we’ve heard good things about making certificates on Microsoft Paint.
Anyhoo, if you’d prefer to live the lux life, rather than engage in lux calculus, get in touch with us to talk about lighting designs and light beams.