“It is one of the fundamental principles of aerial perspective that the dark tones of a landscape are the first ones affected by the interposed veil of atmosphere.
“A green tree in the foreground, for instance, will appear dark green in the shadows; but you don’t have to get very far away from it before that green disappears entirely, especially if you are looking toward the sun. In the middle distance the shadow areas in the foliage will take on a violet tone, while the sunlit parts are only a little cooler green than they are close up.
“At a distance of several miles this violet will become more and more blue. By this time air will have begun to affect the sunlit parts also, and the green will begin to disappear. A forest-covered mountain fifteen or twenty miles away, in clear air, will probably appear of a violet hue; but if it is fifty or sixty miles, it will be a clear pale blue.
“Another thing to remember is the effect of air on values. Here again it is the darkest tones that are affected first. The deep shadows and the halftones melt together, while the detail is still distinct in the highlights. As the distance increases, both dark and light objects approach the sky in value; but the light objects will hold out the longest.
Objects lighter than the sky grow darker as they recede, instead of lighter, and they grow warmer instead of cooler. You can observe this on a clear day when there are cumulus clouds in the sky. As the clouds recede they become yellowish, and those away off in the distance will be pinkish. (Note: the above image is the painted background from a Peabody Museum diorama.)
“The reason for this diverse behavior of light and dark objects is to be found in the fact that the air absorbs and scatters light of the shorter wavelengths toward the blue and violet end of the spectrum, while transmitting the reds and yellows whose wavelength is longer. Toward sunset, when the slanting rays of sunlight have to traverse a thicker layer of air, still longer wavelengths are filtered out and the sun appears red.
“Do you remember the band of pinkish light across the top of the mountain in the Jaguar group? What happens here is that all the blues are filtered out high up in the sky, and by the time the sunlight reaches the lower air and falls in front of the mountain, it is decidedly reddish. So you are looking at the mountain through a reddish veil instead of a bluish one.
“The most important thing to remember in painting a sunset effect is to keep all your tones harmonious and consistent. And if you have bright clouds, yellow or rose-colored in the blue sky, don’t paint your sky too blue. Keep the blue very quiet. That way your clouds will appear much more brilliant and luminous.”
According to his assistant, Ruth Morrill, Wilson used the following nine colors, along with Permalba white.
Cadmium yellow pale
Cadmium yellow deep
“He could make anything he wanted from those colors,” Ruth Morrill said. He did not use black and only rarely used browns. He regularly premixed graduated tints of each of the primaries on his palette before commencing to paint.
According to one of Wilson’s letters, the entire distance of the Connecticut shoreline diorama (above) was painted with ultramarine, light red and yellow ochre. “It is astonishing what variety you can get with these three,” he wrote, “especially since both the red and the yellow are rather subdued colors. I recommend your experimenting to see what you can do with just these three. They are bound to impart a mellow quality to the greens, which is a good thing.”
As blog reader Armand Cabrera pointed out, there’s a good article on JPW in American Art Review, December 2000. There’s another detailed article in the Peabody Museum publication Curator, October 2000. Both articles are written by Michael Anderson, who has compiled 20 years of research about Wilson. I am grateful to him and Ruth Morrill for sharing their unpublished interview material.
Jaguar image courtesy Supreme Fiction, which has an interview with Stephen Quinn about the art of the diorama, link.