Changing Light from Dawn to Dusk

How sunlight and skylight affect foliage colors

One of the ways you can make a representational painting ‘hang together’ is to make sure the light falling on objects is consistent throughout.  Does everything say ‘cloudy day’?  Is it saying ‘sunrise’?  And what about your foliage? That can be tricky!  If it isn’t consistent with the light you’re expressing in the rest of your painting, greens, in particular, can be jarring and overwhelm the painting. 

This is about the natural light that illuminates your leaves and everything else in your painting, because the color of surfaces depends not just on the actual color of the surfaces themselves, but on the light source used to illuminate them.

Light typically comes from three sources – sunlight, skylight, and reflection from adjacent objects.  This tip is about the first two: sunlight and skylight.  These light sources show daily changes in light intensity (brightness) and light temperature (warm color and cool color).

Through the day, direct sunlight ranges from a rosy dawn to intensely bright greenish-white at noon, to scarlet at sunset.  When sunlight and skylight are combined, it can range from pale yellow at dawn to cerulean or greenish blue at noon to a deep yellow at sunset.  But keep in mind, lots of atmospheric conditions can affect sunlight and skylight, like humidity, clouds, dust - and as we know too well - smoke.

Out of curiosity, I shot one photograph every hour to watch leaf colors change through the day.  Here’s what I found:

In the early morning, the plants had no direct sunlight.  (That means the primary light source was from the sky above.)

·         Greens were tinted bluer

·         Greens became darker, with less contrast between leaves and shadow.

As morning moved to noon, the plants received direct sunlight.

·         Leaves were lighter and more saturated (clearer color).

·         Greens became more yellow.

·         Plants had more contrast between leaves and shadow.

From noon to sunset,

·         Brightness decreased.

·         Color saturation decreased (leaves became grayer).

·         Greens shifted back towards a bluer tint.

Learn more by watching the video on this subject on the Rancho Cordova Arts Channel of YouTube: Watercolor 101: Leaf Greens IV–Leaf Colors Dawn to Dusk with Marsha Mason