4000K Confusion, 4K Immersion, or Self-Inflicted Contusion?!?

4000K Confusion, 4K Immersion, or Self-Inflicted Contusion?!?

How do we make sense of lighting colors, what do these numbers mean,

and how do they relate to terms like Soft White, Bright White, Daylight, etc.?

These questions are the import of this article. Lets get started.

A long long time ago, a scientist invented a temperature scale. They called him Lord Kelvin. He was a Brit named William Thomson. Like the Fahrenheit and Celsius scales, it was based on water freezing and boiling points, 273 K and 373 K, respectively. Lord Kelvin heated a block of carbon and as the temperature rose, the glow emitted equated to the numbers we see on lamps today. 2200 K,  3000 K, 4000 K, 5000 K, etc..  

For this discussion, below 2000 K is like candle light, 5000 K is bright white, and everything in between is the most common lighting temperature we use in our homes and offices today.

Here is a visual.

What different manufacturers call these temperature colors in Kelvin help us to get an idea of the feel the lamp will bring. Soft, warm, cool, daylight etc....

The important thing for us to remember is, to match the color, and to use this knowledge to get the right lamp the first time to match what you already have installed or to make sure when they arrive they will all have the same spectrum of light. 

Your old fashioned warm lighting would be 2200K-2700K.

Most lighting now is 2700K-3000K-4000K.

If you want bright white light get 5000K which is still easy to find in many styles but going above this gets into commercial lighting and the subject of another blog.  Most people are happy with 3000K which happens to be right in the middle from 2000K-5000K but use the temperature for the feel you want to bask in.

More representative examples of some of the warmer lighting temperature for lamps:  

2200 K 2200 K temperature rated lamp           2700 K 2700 K temperature rated lamp, bulb       3000 K 3000 K temperature rated lamp, bulb

Going into the 4000 K and 5000 K is perfect for task lighting or under cabinet.

The thousands K we can thank Lord Kelvin for heating up a carbon block and recorded the glow equated to a temperature of his scale.  Atleast now we can select the color temperature we want and know what we are getting with confidence.  Happy lighting.