Wednesday, November 14, 2012

Artist Tip #6 - Understanding Cast Shadows (Part 3)

Our last tip addressed the direction of cast shadows in backlit scenes.  In this final tip, I'll discuss a few more details that will help your cast shadows make your paintings more pleasing.

I suggest you do not paint cast shadows separately, but paint them right over the already-painted object they are falling on.  With watercolor, this has to be done after the base color is bone-dry, or a muddy mess will be the result.

Let's consider shadow color.  Shadows can and do have color, and we can make our paintings more entertaining by emphasizing or exaggerating their color.  I haven't found a color formula for shadows that always works, but you can consider the following possibile approaches.  
  • For outdoor scenes, shadows often tend towards blue or purple due to the cool nature of the light from the sky.
  • A different approach involves painting over the base color with its complement.  For example, on a yellow object, a purple hue often works very well to represent a cast shadow.
  • Finally, cast shadows can be livened up by painting the basic shadow and then charging in other colors.  For an impressionistic-style painting, it's not really necessary to "explain" where these charged colors come from, but claiming "color bounce" from nearby objects is a great excuse if you feel you need one.
Actual cast shadows are harder-edge near the object casting the shadow, and become softer-edged as the distance from the object increases.  Leaving a few soft or rough edges on cast shadows makes them look more like shadows and less like dark shapes cut out and glued down.  Of course, this is true for all shapes in our paintings - we need to vary the edges to integrate them into the painting.

I've found that when shadows fall mainly side-to-side in my paintings, they look best when all painted in roughly the same direction.  They also look better if their shape doesn't exactly match the shape of the object casting the shadow, but simply suggests that shape.  Care should be taken to connect shadows to the objects that cast them, so they "belong" to one another without an obvious change in color or value.  When figures cast shadows on the ground, these shadows "anchor" the figures in place and help to make them more realistic.

Finally, often a shadow is needed in a painting for design or composition reasons.  For example, many paintings can be improved by adding a dark shadow in the foreground, at the bottom of the painting.  This sort of shadow helps to lead the viewer's eye over the foreground and into the painting.  Such shadows can be added when needed without having to explain what object outside the picture plane is causing them.  I've included a painting with such a "dark doorstep" to illustrate this design technique.

If you'd like to review previous artist tips, you can find them all by going to the search box in the right-hand column of this blog, and searching for artist tips.

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