I'm Joey Nicotera. I've been lighting up all kinds of environments and objects for most of my life, and I have seen a LOT of changes. Lighting has evolved from something that was necessity based to something that is now choice-based. No longer are we limited to just on/off or even just dimming. Our lighting can be any color we want, any brightness we want, and can even work with us to enhance our mood and our lives in general. With all those choices comes a whole slew of new terms and concepts. Over the next few weeks, I'll be blogging about the new ways to talk about light, and be showing you some cool things you can do with the new generation of light sources, namely Ilumi. Please let me know in the comments if there is anything you like to learn or read more about.
Without further ado....
Let's discuss the LUMEN
The lumen is the standard unit of luminous flux. Luminous flux is the measure of perceived power of light by the human eye. We measure luminous flux in lumens, just as we might measure speed in miles per hour. Why don't we just say "brightness"? Well, luminous flux is measurable, unlike brightness which is a perception. Brightness means something different to everyone, just like 'fast' to one person is 'slow' to another. "Speed" however, can be measured. That said, you'll always see me writing "appear brighter" and "perceived brightness", since brightness is different for everyone.
Speed is to miles per hour
Luminous flux is to lumens
The more lumens a light source outputs, the brighter the objects being lit by said source will appear. Notice I again said "appear". That's because lumens do not take into account the area over which the light is spread. A light source emitting 1000 lumens in a room that's 8x8 with 8' high ceilings will make that room appear much brighter than if that same light source was lighting a football stadium. Lumens over an area is measured in 'lux', but more on that in another post.
How do you know how many lumens you should be looking for in a light source? That's a good question. Generally, if your light source is a smart fixture or one that can be dimmed, the more lumens, the better. You can always dim a source, you can't brighten it past its maximum. You can however, add more than one of the same source to increase your lumen output. In the case of ilumi, that's certainly something you'd want to do, because five different colors at the same time (or 50 for that matter) are always more fun than one. Plus, having multiple light sources in an area is the recommended way to light a space, but more on *that* in another post as well.
What about watts?
Ah, the watt, the standard by which light bulbs have been measured for decades. Forgetaboutit. A watt is a measure of energy. Yep, that's right, energy, not light. You pay your electric company for providing you with energy, usually by the kilowatts you use per hour. A 60W incandescent bulb is only telling you how much energy it is going to consume, not how many lumens it outputs (though on average it's about 800 lumens). An ilumi LED fixture outputting the same 800 lumens maxes out at 10W, and it's WAY more fun and useful. It can precisely reproduce the color of light that the old 60W emits, and be any one of 16 million+ colors whenever you choose.
Thanks for reading, and come on back next week as we discuss: Color temperature and CRI!