This is the Gremlin’s Hall, an older render (see http://www.bryce5.com/details.php?image_id=4379 ) made up as anaglyph. Now I also undertand why it was so difficult to set up the lights.
The toe-in angle is set for something very near to the eyes. Therefore, the eyes have a bit of a problem to focus. Also, the distance between the eyes is large, around double of an human. This makes the gremlins small (they are small guys, after all) and their cave huge.
Best start at the lower left corner, where the landscape is nearest. Then move on to the waving guy, then continue right until you get the sitting chap fucused. At this time, foreground and middleground are easy to behold. Now move up your eyes and discover how vast this cave actually is.
That’s incredible, took me a couple of minutes to get the focus, but what a revelation.