He changed his name to Alexander Hammid when he became a citizen of the United States in 1942. He is best-known for his work in documentary film, both as a director, cameraman and editor.

According to Jaroslav Andel's biography of Hackenschmied, in 1930, Hackenschmied created his first film Bezúčelná procházka (Aimless Walk) which inaugurated the movement of avant-garde film in Czechoslovakia. The same year he also organized the Exhibition of New Czech Photography in the Aventinska Mansarda -- a showcase for artists of the Aventinum publishing house in Prague -- and the first show of European avant-garde film in the Kotva Cinema, also in Prague. He also published a number of articles on photography and film, in which he formulated the new aesthetics of both fields.[1]

Before emigrating from Czechoslovakia, Hackenschmied worked for the Bata Film Studio in Zlín, founded by Jan Antonín Baťa in the 1930s who hired young filmmakers and artists to develop modern films, primarily for advertising. While employed there, Hackenschmied made numerous advertising and documentary films, one of the most famous was directed by Elmar Klos in 1937, entitled The Highway Sings, showing auto tires in motion.

During the late 1930s he collaborated with the American filmmaker Herbert Kline on the feature-length documentary Crisis (1939) and moved to the USA where he met and worked with Deren on her first film Meshes of the Afternoon (1943). He also directed the documentaries The Forgotten Village (1941), The Valley of the Tennessee (1944), and A Better Tomorrow (1945). Hammid also made the 22-minute short The Private Life of a Cat (1947) while married to Deren and shot entirely in their Morton Street apartment in Manhattan. This short film was part narrative, part documentary about cats and their daily lives. The film starts off with two cats, a male and a female. The female is eventually impregnated by the male cat, and begins to search for shelter for when she gives birth to her kittens. The film shows her giving birth to five kittens in graphic detail.

In 1944, he directed a documentary featuring conductor Arturo Toscanini, Hymn of the Nations, produced by the Office of War Information. His documentary Library of Congress (1945) was nominated for an Academy Award for Best Short Documentary. Through the 50's and 60's Hammid made documentaries. In 1951, Hackenschmied and Gian Carlo Menotti co-directed the film version of Menotti's opera The Medium.

In 1964, Hammid directed his final film, To Be Alive!. which was shown at the 1964 New York World's Fair and won an Academy Award for Best Documentary Short in 1965.

Hammid worked in partnership with filmmaker Francis Thompson (1908-2003) for over 25 years, producing numerous “in-house” documentaries as well as several films for general viewership. One of the most notable of these is the first IMAX format film, TO FLY! which premiered at the Smithsonian Institution’s National Air and Space Museum (NASM) at the museum’s grand opening celebration on July 1, 1976. Produced in conjunction with MacGillivray Freeman Films, it continues to play regularly at the Air and Space Museum.

During his years with Francis Thompson, Inc. Hammid went on to be involved with several other early Imax films. Graham Ferguson, owner of the Imax Corp. (speaking at Francis Thompson’s memorial service in 2004) recalled how he had wanted Hammid and Thompson to make the first commercial Imax films because of their extensive work in earlier large-scale multi-screen films including To Be Alive! (which won an Oscar after being shown at the New York World's Fair in 1964), We Are Young (on six screens for the Montreal World's Fair/Expo 67 in 1967) and US (for San Antonio's Hemisfair in 1969).