W A Bentley (1865-1931 )
Photographed snowflakes from 1895-1931 using a contraption of his own devising. It was a combination of a camera bellows box with an attached microscope. He had to do all his work outdoors so that the snowflakes would not melt.
Work illustrated in: “Snow Crystals”, McGraw Hill and the United States Weather Bureau, 1931
And, “Snowflakes in Photography”, Dover, 2000