[1] Kettelhut is considered one of the most important artists in the history of early German cinema, mainly for his set direction for Die Nibelungen (1924) and his design and visual effects for Metropolis (1927).

[1] After being discharged at the end of the First World War his old colleagues, Hunte and Karl Vollbrecht, found Kettelhut employment at Martin Jacoby-Boy's design agency in Berlin.

After producing designs on both parts of 1921's The Indian Tomb, Kettelhut was hired to work on Lang's Dr. Mabuse the Gambler (1922), where he was reunited with Hunte and Vollbrecht.

[2] Lang kept faith with his old team and with Hunte as lead, Vollbrecht and Kettelhut were brought in to design the cityscape central to the sci-fi dystopia of the film.

[7] Rittau and Kettelhut worked closely, not only to realise Lang's vision, but also on early special effects to bring the enormity of the city to life.

Unlike their contemporaries, Robert Herlth (Faust) and Walter Reimann (The Cabinet of Dr. Caligari), Hunte and Kettelhut preferred to approach a challenge by looking at the economic restrictions and technical difficulties to ensure they did not hit problems at construction.

[2] In 1928 Kettelhut provided art direction for Paul Czinner's drama Doña Juana, and Ungarische Rhapsodie a romantic film starring a young Dita Parlo.

à vos ordres!, The Love Waltz and Quick) and Hans Albers adventures (Asphalt, Bombs on Monte Carlo and F.P.1 antwortet nicht).

Kettelhut's Asphalt street was a fully functioning 760-foot-long set that allowed for ten camera positions and whose "day-lighting" of 2,000 lamps consumed the electrical supply comparable to a small city.

He found himself working with German directors such as Paul Martin, Reinhold Schünzel and Arthur Robison, producing mainly comedies for home-grown talent like Willy Fritsch.

From 1937 he struck a strong professional relationship with director Georg Jacoby, and worked on a string of musicals with him, including Gasparone (1937), Der Vorhang fällt (1939), Kora Terry (1940) and Frauen sind doch bessere Diplomaten (1941).

Frauen sind doch bessere Diplomaten (Women Are Better Diplomats) was a long shoot and went over budget, mainly due to problems with filming in the newly developed Agfacolor.

Kettelhut at first found himself designing sets for films similar to those he had been working on during the 1940s, with another Georg Jacoby musical Sensation in San Remo (1951), starring Marika Rökk.

In the late 1950s, Kettelhut contributed outstanding design sets to two submarine dramas, the sympathetic anti-war tale Haie und kleine Fische [de] (Sharks and Little Fish) and the loose biographical film U 47 – Kapitänleutnant Prien.