Not to be too picky... but water is not black in IR imaging because it absorbs so much IR radiation. It is true that liquid water reflects very little IR radia

Not to be too picky... but water is not black in IR imaging because it absorbs so much IR radiation. It is true that liquid water reflects very little IR radiation (less than 10%)... but water also emits thermal radiation (important to note that IR emission from water is quite different from black-body sources). Water that looks black in an image is simply emitting less IR radiation than other objects in the image... typically because the water is colder. See: https://www.youtube.com/watch?v=xcyU8oXBn6k https://www.youtube.com/watch?v=xcyU8oXBn6k <-- used to work on infrared detector development and IR radiometry