Monday, September 8, 2014

Complementary Shadows

Arbi asks: "Could you please explain about 'complementary shadows?' Some attribute complementary shadows to the Impressionist habit of painting the reflected color of blue sky in shadows, and others attribute it to simultaneous-contrast. Is it real? Do you use it in your painting, and how do you implement it?"
Maxfield Parrish

Arbi, it's a little of both. In most sunny conditions, shadows really are in a complementary color range compared to the sunlit surfaces because they're lit by the relatively blue skylight.

By contrast, the sunlit surfaces are lit by the sum of the sunlight and the skylight, with the sunlight dominating. It's easy to demonstrate this with a camera that is color balanced to sunlit white paper. When you take the same white paper and photograph it again in shadow, it's clearly bluer.

The effect is heightened late in the day as the sun is lower in the sky. More of the short-wavelength is scattered out of the sunlight, leaving more orange or red light, and making the color contrast between light and shadow more obvious.

(A brief caution on the above: the shadow side of any object receives not only skylight, but also reflected light from other sources, so if those sources of reflected light are very warm, and the sky is blocked by trees or clouds, the shadow might be very warm, too.)

These are all from the shadow side of a white building. From the post "A White Building in Shadow"
At the same time, our visual system is set up in such a way that exposure to any color causes adjacent colors to appear complementary, so a yellow square next to a gray square will make the gray square look bluer.

This is an effect I like to use a lot, not only to simulate the "Golden Hour" time of day, but also in small ways, to alternate relatively warm and cool colors throughout a picture.
Previously on GJ:
Golden Hour
Induced Color
Warm and Cool Colors
A White Building in Shadow
Color and Light: A Guide for the Realist Painter on Amazon


Dustin Wilson said...

I went to college for graphic design. Painting wasn't a required course, but I took two of them for art electives. They were the most expensive classes I took the entire time I was in school because of the supplies, and they were the most useful. I'd taken color theory prior as two classes on that were required and was familiar with it from also doing color theory exercises in high school art, but everything really clicked when we did landscape painting and he instructed us to pay attention to the colors in the shadows.

We were let loose into the garden area and were instructed to paint in our sketchbooks with gouache random things we saw. He told us as we were painting to record the time and if it was overcast where we were sitting (because it was a partly cloudy day). We were to closely look at the shadows and even exaggerate the color if we wanted to. The class lasted four hours, and we started around 8:30 and ended about 11:30 so he could give his lecture at the end. That lecture consisted of his holding up our sketchbooks and explaining to us why the shadows were that way while simultaneously explaining the science behind it. Sunlight changes a lot during that time frame. It's probably the single most important lecture I received in my four years of school there.

Matthew Larson said...

Thanks again for such a great post. What about analyzing some Frank Tenney Johnson nocturnes with this principal in mind.