I don't know ... I'd say it's not ridiculous at all, if you think of the shadows and gray values/lighting as being distinct parts of the scene, just as much as the shapes of the actual subject matter. There's a reason why painters do a value study before they start a painting, after all. It's *hard* to add something at a later stage it wasn't planned in the beginning.

Like I said earlier, lighting is definitely one of my "artistic things to work on". Maybe I'll bump it up the to-do queue ... it might be fun to do some pieces of art that are designed to work on my dealing with light and shade.