that was something i was going for
well, this is how it was explained to me: cast shadows are usually darker and with a more defined shape, and form shadow is the shadow on the object on the oposite side of the light source that gives the object it-s form but is lighter and softer than cast shadow
there-s something about it here http://www.kingslan.com/newsletters/shadows.pdf
honestly, I-m still trying to wrap my head around it, i thought the shadow is what gives the object it's form, and didn't rly notice the difference. But, when you pay a bit of attention, you can notice it
For example my black and white male portrait...he is sitting in the shadow of something, but that is not clear because there is no cast shadow, i treated them the same
I dont know if anything of this makes sense xD