Here is a problem that showed up on my exam that I couldn't find any variation online. A stick of length L is depth D in the water. The stick is parallel to the surface of the water, and the viewer (in air) is looking down in the water right over the middle of the stick. What is the apparent LENGTH of the stick? For me, I thought that the virtual image both ends of the stick are right above the ends of the stick, so the stick would appear shallower but preserve the same length. However, the answer is wrong, and in the ray diagram from the solutions, the virtual ray that the viewer sees originates at the same depth as the stick, which is the cause of the length difference, but I don't understand at all why that would be the case. Since if draw two rays, refract them, then backtrace the refracted rays, they always appear right over the ends of the real stick. Could someone tell me what exactly is wrong with my line of thinking, that the virtual image appears right over the stick so the stick's virtual length should be unchanged?