Friday, April 24, 2015

The Eerie 'Pea Soup" Color Before The Storm...

Ever Notice The Ambient 'Pea Soup' Color
Before a Major Storm or Tornado?

Eerie magical lighting. Sometimes it is just before a storm, sometimes near dusk or dawn. There are times the light just seems odd, dreamlike or really unusual. It seems hard to catch on film, but even florescent lighting has an element of it. Something unnatural. 

Our world of color is much more complex than RGB values. In our industry, we are accustomed to expressing every color by some triad of numbers; RGB being the most common. However, actual color is a spectrum, not a color point. What we perceive is typically the peak of the spectrum, red, green, purple, whatever. Turns out however that RGB is not a unique spectrum. That is there are many, many different spectrums that can take us to any given RGB value. It is this difference between the spectrum and the RGB color point that make magic.

Let’s look at what we humans evolved with, sunlight. The color spectrum of sunlight is pretty flat. That is, all the colors are well represented from the sun. Plants have a sort of color vision, in that they absorb light mostly in two narrow colors (around 400 & 600 nm). This sunlight is what we are used to. 

Photographers are aware that typical florescent lighting is not just a color, it is also missing some colors. This is why, no matter what post color you add to offset florescent, it never looks quite right. All artificial light spectrums look off. 

So below is a spectrum graph I made, showing that magical and unpleasant light is not about the color, but about unusual valleys and peaks in color. It might be the same color as a smooth curve, but those spectral holes create the magical nature of light.

[Geeky sidebar. I decided to illustrate this post with an ITRI certified spectrometer. The unit I am using, the MK350 records spectra onto memory cards so I can share the spectrums with you. I use this device for analyzing light prior to filming and then for precise color control all the way through to exhibition.]