Artist Scott Waddell provides a short video on painting the effects of light on his blog https://scottssketchbook.blogspot.com. He gives details and examples on how light affects objects that reflect light, absorb light or are translucent. Also, look for his video titled “Webisode 7: Conceptural Edge” where he provides details on how to identify soft and hard edges based on the light source in use.
Scott Waddell
For extended videos, check out Scott’s web site at https://www.scottwaddellfinearts.com/Videos.htm where you can purchase his training material.