[5] Owner of a pharmacy on Istiklal Avenue, his father had a wide circle of friends from the art world of the period.

During his high school years, he worked in movie studios and attended drama courses held by Muhsin Ertuğrul, the founder of modern Turkish theater.

After completing his military service in 1961, Güler was employed by the Turkish magazine Hayat as head of its photographic department.

[6][3] About this time, he met Henri Cartier-Bresson and Marc Riboud, who recruited him for the Magnum Photos agency, which he joined (though later withdrew from).

His works were exhibited in 1968 in 10 Masters of Color Photography at the New York Museum of Modern Art and at Photokina Fair in Cologne, Germany.

[6][3] Güler traveled on assignment to Iran, Kazakhstan, Afghanistan, Pakistan, India, Kenya, New Guinea, Borneo, as well as all parts of Turkey.

[8] In the 1970s he photographed politicians and artists such as Indira Gandhi, Maria Callas, John Berger, Bertrand Russell, Willy Brandt, Alfred Hitchcock,[2] Ansel Adams, Imogen Cunningham, Marc Chagall, Salvador Dalí[2] and Pablo Picasso.

Güler's work is collected by the National Library of France in Paris; the George Eastman Museum in Rochester, New York; University of Nebraska-Lincoln Sheldon Memorial Art Gallery; Museum Ludwig Köln, and Das imaginäre Photo-Museum, Köln.