Here are a few grids I whipped up to help you with your light source. Print them onto Acetate. They are designed to be 6 x 6 in size, or you can buy Shadows and Shading by Marianne Walker and get some fabulous templates included, as well as some fantastic information on shading and shadows.
I never thought about using something like this to determine a light source. Try to do it in my head, but this makes much more sense. It's like a "light" went off in my brain. Thanks so much
Thank you! I will try these. I do it in my head as well, but I'm not always successful.
Thank you very much for these light guides. They will be quite helpful.