Exploration of a Sphere Part 3: How Cast Shadows Behave

Yesterday I discussed core shadows and reflected light.  One of my students asked a really good question about reflected light, which I answered at the bottom of the post here.  Today I am going to discuss how cast shadows behave.

Did you ever paint an object which appears to float?  That is because you haven't painted its cast shadow.  Did you ever paint an object which appears to be falling off the canvas?  That is because you have the angle of the cast shadow wrong.  (I know the sphere above is rolling down hill, but that is because I can't hold my camera straight.  I swear it is straight in real life.)  Did you ever paint an object with a cast shadow, but it still doesn't seem to be firmly planted on the surface it is sitting on?  That is because the cast shadow is not quite dark enough right up against the object.  Did you ever paint a cast shadow which appears instead to be a hole down which your object is going to fall, instead of a shadow?  That is because you got the value of the shadow too dark and too even and the edges too evenly hard.

Cast shadows are darkest right up against the object and they get slightly lighter in value as they move away from the object.  Sometimes they will have reflected light in them too.  The light comes from the main light source, hits the table, bounces back up onto the sphere and creates the reflected light on the sphere.  But look closely, sometimes the light is strong enough to continue its journey, bouncing off the sphere and back into the cast shadow.  Yikes, I know, you have to look closely.

Edges of shadows tend to be harder/sharper closer to the object casting them and get softer/fuzzier as they move away from the object.  I will talk some more about edges tomorrow.