RayTracing in General Relativity: How Einstein would look passing near a black hole
1.3 Meg GIF movie
Note how, as the image gets closer to the black hole, it not only distorts, but actually pojects a reflection of itself on the other side of the black hole. That happens in gravitational lensing.
(rendered by Daniel Weiskopf from the Max Planck Institute in Germany. Image and movie-rendering in GR recently became my own (part-time) postgrad project of choice)