Can you imagine it? Chilling air makes your nose tingle; shades of cool mix with shades of warm, seen in refraction. And you hurry to make a photo, only to discover later on that it (oh, dear) didn’t capture subtle color nuances of the ice.
But stop - let’s simulate it in 3d, build the world around it, breathe the life into it and capture its beauty in refraction.
In the end, I don’t care whether it is physically correct, I want it to be aesthetically correct.
If the entirety of the foreground (not just the ice) is all CG, then I can say that this image has some of the absolute most convincing frozen material shading ever made in Cycles (not only for the overall look, but also because of the many subtle details and touches throughout).
Without a doubt, few would ever be able to tell that this is CG without being told it is, it’s that good.