During my longer than expected hiatus from art because I have a lovely boy who is still not sleeping much, I am still thinking of art almost constantly.
My family lives in Argentina so I promised that I was going to send them photos of the baby every day, consequently, I am taking a crap load of photos. During my last photoshot I had the luck to witness what we always read about in the books, but in real life is hard to see.
In theory, the shadow cast by an object is the complementary color of the light that bathes that object, and when light bounces off of an object the color of said object is reflected in another surface. The problem is that rarely light is one color (white light being the sum of all colors) so the shadows are not the complementary too obviously, and we perceive them rather gray. However, in art, a gray shadow makes things look flat and boring. Additionally, there is usually so much noise that the reflections of colors is not quite clearly seen most of the times.
Well, I had a Dr. Seuss book on my coffee table, a party edition of One Fish Two Fish Blue Fish Red Fish (yes, my readings have turned very cultural!) and the cover is a metallic yellow, the sun was coming in, bouncing off of the book, projecting the light onto the ceiling. This was perfect to generate the purple shadow that in theory should be there:
I was so excited that I had to take a photo!
Later, while shooting photos of Ignacio I saw that one of his toys was reflecting beautifully on him!
If you notice the light is coming from the left, it bounces on the vertical face of the cubes (the one we barely see) and it is reflected onto his skin. Notice that the reflection happens only in this direction because of the path of light, and also because of the texture of the surfaces. If instead of his skin we would have a shiny surface (like metal) the light might bounce off again in the opposite direction.
Look at the first photo and notice how saturated the reflected light is! This is always important to keep in mind to make your paintings vibrant and life-like.