Here's the problem: Here's what I understand: I know what a biconcave lens looks like, and how it behaves (for the most part). Of course I know that the index of refraction is ~1.00. And since the radii are equal that makes the equation somewhat easier. The thick lens equation is: (Sorry I am not yet familiar with LaTex, so just *imagine* that (1/R1)-(1/R2) isn't there). What I don't understand: Where is the image diverging from? "Parallel rays from the central axis convirge into a reflected and transmitted image"..does this just mean where the rays convirge? Any guidance would be appreciated. Thanks as always!