Ray diagrams can be one of the trickiest things to really get in introductory physics. There are a lot of pieces that have to be done just so and the rules seem arbitrary.
This collection of 48 slides leads students slowly and clearly through all the major ray diagrams for lenses and mirrors in a conversational style. I take the time to explain not just the HOW, but also the WHY of what's going on.
The slides also present the equations for calculating focal length and magnification, with each variable clearly explained. Two step-by-step standard practice problems are also included in the notes.
Materials by Science Josh