I suspected that refraction wouldn't work on its own with an imported background image, just like raytraced reflections, but I didn't feel like testing it. It didn't occur to me that you could simply force it by plugging an image_map of the background into the node's background channel. Thanks for the tip. The first animation (the headshot) used a textured backdrop. The second (the walk) used one of As Shanim's environment props. ernyoka1: I had trouble using refraction at first, until I realized that it effectively created the illusion of transparency on its own. Using real transparency on refractive materials was weakening the desired effect.