Fish visual photography

Divers watching fish underwater is not a matter of height, but a matter of distance. People's eyes are in direct contact with water, which will cause blurred scenery. Only by putting on a mirror and forming an air layer between the mirror and the eyes can we see the underwater scene clearly. The objects seen in the water are closer than those seen on the land, and they have visual magnification, so it is bigger to see fish in the water than on the land.