Hadi used a primitive wooden box called a "kamra-e-faoree" that served as both his camera and a self-contained darkroom. Using sunlight and 19th-century photography skills largely forgotten in the West, he could produce a black-and-white portrait within minutes -- first making a paper negative, then photographing the negative to make a positive print.
From 1992 to 1994, Hadi documented the injuries of 10,000 of the foundation's aid recipients. One photograph he took in early 1993 became the world's most famous Afghan box-camera portrait: the only known photo of future Taliban leader Mullah Mohammad Omar.
In April 2021, Vienna-based Fraglich Publishing released some of Hadi’s other Afghan box-camera photos in a book titled Disasters Of War: Portraits By Khalid Hadi.