This week the photography world mourns the passing of Lennart Nilsson at 94. Nilsson was a Swedish photographer, who used micro-cameras, endoscopic fiberscopes, electron microscopes, and specially designed lenses to photograph the development of the human embryo from fertilization through maturation. His images both still and video were literally breathtaking and left the technical-minded wondering just how did he do that.

Mr. Nilsson said of himself on his website, “I’m just a photographer who happened to be fascinated with mankind.” He was famous both for his book that took us into the terrain of the human body, as if we were exploring the moon – “Behold Man: A Photographic Journey of Discovery Inside the Body,” in collaboration with pathologist Jan Lindberg, and for his landmark book on human development, “A Child is Born.”

With Nilsson’s passing we lose a pioneer and explorer, who truly pushed aside the limits of photography and of human understanding.