Attached Link: http://www.dualheights.se/caustics/

> Quote - Most of the images of submarines I see are actually renders and I suppose if they are convincing, it would be fair to copy what they look like. But I'd prefer real photos.

I would think that most real photos of submarines underwater would be murky and uninteresting. They don't venture into those shallow, clear tropical waters that make for attractive photos very often. By a similar token, although I don't know the physics, pretty effects like caustics drop off quite quickly with depth. You might need them for the jug of water in a sunbeam (the new CGI standard image, now replacing reflecting spheres over water) and for a swimming pool, but not for a submarine unless it was close to the surface.

There's a free (fake) caustics generator at the link, for anyone who doesn't know about it. I've seen its output being sold at stock photo sites, but that's another matter entirely...