He founded the Camerapix company in 1963 in Dar es Salaam and moved the company to Nairobi three years later. During the 1970s, he became one of the most relied-upon African news photographers, reporting on wars and coups all through the continent, and his pictures were often used by Western news media. Amin’s most influential moment came when his filming, along with Michael Buerk’s reporting of the 1984 Ethiopian famine brought international attention to the crisis and eventually helped start the charity wave that resulted in Live Aid concerts.

Apart from the Ethiopian famine, he contributed exclusive photos of the fall of Idi Amin and of Mengistu Haile Mariam, and was the author of numerous books, including Journey Through Pakistan, Pilgrimage to Mecca, and covered various themes like East African Wildlife and the Uganda Railway. Amin also published issues of Selamta, the Ethiopian Airlines in-flight magazine.

Amin was not only active in Africa, but also in the Middle East. He covered the Palestinian Black September uprising to seize control of Jordan in September 1970. He was able to move among the Palestinian forces where Western journalists could not.

In 1991, Amin lost his left arm during an ammunition dump explosion in Ethiopia during the Ethiopian Civil War.