If I remember correctly, the percentage of light that passes through a column of water exponentially decays with distance, like stacking a bunch of fixed-percen

If I remember correctly, the percentage of light that passes through a column of water exponentially decays with distance, like stacking a bunch of fixed-percentage optical filters on top of each other. They’re using parallax shift between multiple images to generate a depth map, so they have a measure of the amount of water obscuring each pixel. I’m not sure how they’re finding the optical properties of the water; there’s something about using the darkest pixels in the image for calibration that I didn’t quite follow.