Sunday, August 7, 2011

Sunlit Color

Extreme chroma color chart in sunlight. Painted by E. Anzini.
This is one of many landscape assignments Reilly gave his students. I had my summer intern recreate this problem for the blog. It is an exercise in creating the look of sunlight, in this case a high chroma color chart in light and shade. The challenge is finding the correct value and color temperature. Reilly first required the students to create a chart in neutral gray to get the values right. The next challenge was find the right color temperature in the light and in the shadow.



High chroma color chart

We began by creating an array of hues in full chroma, sometimes out-of-the-tube and sometimes adding a little white to the darker colors. Next we assigned each color its home value, by comparing them against the values of our neutral grays. Reilly made similar value assignments in the page below. 


Sunlit value range in form lighting.


Using the value scales for sunlight, we reassigned the home values so they would appear to be in light and shade on a sunlit day. An example would be orange with a home value of 7 would be painted 8.5 in the light and 6.5 in the shadow. All the colors in the light were lightened with white and most included a little cadmium yellow (from the warm sun). The shadows included a little ultramarine blue (from the cool sky) as needed. The value and color temperature was adjusted until it looked right. Sunlight creates very little color shift on yellow, more on yellow-red, and more yet on red. It will make green appear yellower, and  blue slightly neutral.


By comparison, moonlight would have a similar approach. White (value 10) becomes 7 in the light and 1 in the shadow. The same orange color with a home value of 7 would now be about 5 in the moonlight and slightly less than 1 in the shadow. The shadows would vary very little in value. Lights would include a yellow-green pigment (moon-color), maybe lemon yellow. The shadows would be influenced by the cool grays on you palette made from lamp black and white.
Moonlit high chroma chart from the Reilly class, courtesy Jerry Allison.
© John Ennis 2011
Next Topic: The Landscape Palette