Conventional Fixtures Full Rainbow divided into 24 filters

[Kvist]

Dear Friends!

I'm going to light up a park for a festival in Copenhagen this summer. There are some major pathways sorrounded by trees. There are exactly 24 trees on each of the pathways and I thought of lighting up each tree with par cans and having the whole pathway stand out as one big rainbow. Therefore I need to know how to divide up the whole color spectrum into 24 filters for 24 trees and thus forming the colors of a rainbow ;-). Are there any suggestions on how to do so?

Cheers

 

[Zel]

Presuming you're looking for just the filter spectrum I would start with the obvious ROY-G-BIV then select enough intermediate filters to fill in between the main colors. Was that what you were looking for or was there more to it?

 

[Kvist]

Red: L106
Orange: L05
Yellow: L101
Green: L139
Blue: L119
Indigo: L181
Violet: L707

I'm very much open to suggestions, both for the main colors and the intermediate fillers ;-) But there must be some kind of system to somehow get to the exact right filters? Maybe I should write LEE or Rosco for advice...

 

[derekleffew]

You're off to a great start, Kvist! Now you just need to fill in the blanks.

One could approach it scientifically: if one uses 750 mn as "red" and 390 nm as "violet", your colors should be every 15 nm: 390, 405, 420, ... 735, 750.
Two problem with this approach:
1. Theatrical color filters aren't pure, and contain a range, not a single wavelength.
2. The human eye/brain does not perceive the curve as linear. It has an easier time distinguishing between some colors than others.
The best way to do it is by eye. That's why you're a designer and not a scientist.

I don't know how difficult it would be to obtain an ApolloGel swatchbook in Denmark, but even if you are planning to use LEE Filters, it offers some advantages for a project like this:
1. The colors are in chromatic order, 3000's=Violets, 4000's=Blues, ... 8000's=Reds. (GamColor uses a similar approach.)
2. A full color SED is printed on each dividing page.
You could use the Apollo book to choose the colors, then convert back to LEE.
(Images from Apollo Design | Gel .)


So you just need to add more colors to your initial seven. Be aware that you don't need/won't be able to put two or three between each one. You may find six appropriate colors between Blue and Green, and only one between Red and Orange. And that's fine; the audience will get the idea.

See also Visible spectrum - Wikipedia, the free encyclopedia .

 

[Eriksrocks]

If you're looking for another scientific approach, both Rosco and Lee list their gels colors on their websites using HTML Hex codes, which are hexadecimal representations of RGB values. You could convert the RGB values to HSL/HSV, and look for colors with similar saturation and lightness values but evenly spaced across the hue spectrum. The hex codes are the companies' best representation of the gels, but keep in mind you can't really represent the entire spectrum of light using only RGB values, so it might be best to just grab a swatchbook and do it by sight.

 

[Kvist]

Thanks for all your advice. After some consideration, I contacted the local Rosco dealer in Copenhagen. I'll be meeting them today, and will try to take it from a scientific approach. I will post our result in this thread as soon as possible ;-)