The term “audiovisual heritage” encompasses a wide range of material, from Charlie Chaplin’s masterworks to the forgotten Danish slapsticks of Pat & patachon, from black-and-white footage from historical newsreels to  yellowed family photos and more. The significance of the preservation and safeguarding of audiovisual heritage is commemorated annually worldwide on 27 October on the initiative of UNESCO. This felt like an apt moment to interview HTW’s Prof. Dr Ulrich Rüdel about the importance of these materials. An expert in film restoration, he is particularly interested in colour processes in film and photography. In the Bachelor’s degree programme Conservation and Restoration/Field Archaeology, Prof. Dr Rüdel has been supervising the specialisation track Audiovisual and Photographic Cultural Heritage – Modern Media since 2015.

Prof. Dr Ulrich Rüdel: As often, this is a question of definition. It certainly pertains to the concept of “moving image and sound”, i.e. time-based media such as film, video, audio tapes and records. The possible inclusion of photography or audiovisual installation art installations may be a matter of debate, but these are mere academic niceties.

Yes, I think so. When asked about the importance of audiovisual cultural heritage, I like to quote filmmaker Martin Scorsese. If memory serves, he once simply explained: “Imagine if we had film footage of Beethoven conducting!” Film and sound are curators of global cultural history.

Indeed. Cultural heritage is disseminated internationally and its preservation is a global task. The monumental silent film “Metropolis” by Fritz Lang ( 1927) is a well-known example. The longest version still in existence today resurfaced in Argentina. Or, as example from HTW’s work: The oldest Korean film (Im Land der Morgenstille [In the Land of Morning Calm 9, 1925) is a German production, i.e. a missionary film that has been safeguarded at a Bavarian monastery until the present day. A Korean student scrutinized it at HTW Berlin under the supervision of Prof. Koerber, my predecessor, who has done so much for film restoration in the German-speaking world, and I served as second supervisor for this fascinating project. Living in Europe, where more funds are available for the preservation of the audiovisual heritage, it is important to acknowledge our privileged position as regards such preservation. In Sri Lanka or India, for example, things look very different – not only in terms of the climate.

Before the pandemic, the number of international students enrolled in the specialisation “Audiovisual and Photographic Cultural Heritage – Modern Media” actually amounted to up to 50 per cent. What’s both exciting and unique about HTW Berlin is that the Bachelor’s programme offers three additional specialisations, namely Conservation and Restoration of Archaeological and Historical Heritage, Modern Materials and Technical Heritage, and Archaeological Excavation Methods – Field Archaeology.

Furthermore, each year, we work with my HTW colleague Prof. Dr. Kähler on a project to analyse and digitise photographic collections in collaboration with the students enrolled in the Museum Studies programme, offering a great deal of synergy within the restoration track and within the entire department.

Certainly. For instance, we are currently examining an exciting basement discovery from the Berlin family of Hermann Kricheldorff in a collaboration with the German Museum of Technology in Berlin. Kricheldorff was a cameraman in the silent film era; in their cellar the family discovered various films, mostly educational films about insects, but also technical equipment. This film rediscovery is now being analysed within one of our student projects. The field is still young and is in need of students to develop and practically implement methods designed to preserve audiovisual heritage.

Well, going ahead and watching the  straight away is a no go. First, it’s subject to a thorough examination. This is performed at a rewind table where individual images can be surveyed and the film print’s condition be examined. Often you have to be very careful. The reels of film found in Berlin mentioned above, for instance, were contaminated with mould, requiring the use of an FFP3 mask and a fume hood for work safety.

Experts look for material traces such as film joins and edge markings which may allow the copy to be dated, and try to find related historical documents such as a so-called film censorship cards, if surviving. In Germany, films were censored prior to public viewing for a long time, and the extremely detailed censorship cards that were created play an important role in our work today. Researchers compare copies and materials, and pay attention to what might appear to be irrelevant details. It often feels like detective work. Is the film on a single reel or has it been split into several smaller reels? Does this mean anything, and if so, what – were they sorted by colour, perhaps? What condition is the film in – possibly brittle or shrunken – and which copying or scanning devices is it compatible with?

The more you know from other fields, i.e. literature, theatre, music and architecture, the more you see. Films are a very wide-ranging c raft and art in conceptual as well as technical terms.

I’ve always enjoyed watching works from the entire history of film, but I also wanted to have deeper background knowledge about them. As a scientist with a doctorate in analytical chemistry, I saw many connections and points of reference between my studies and the field of film material restoration. In 2004, I took the plunge, quit my job in the biotech industry and enjoyed further training at the world’s oldest museum of photography, the George Eastman House in New York. The Eastman House (now George Eastman Museum, GEM)is also an major film archive, which was the perfect place to learn and beginfg pursie my specificinterests. I have a particular interest in the authentic reproduction of film colours and was allowed to work on the original Technicolor research documents kept at GEM. Following up on this this, together with my colleague Dr. Elza Tantcheva-Burdge from Colour Group Britain, I founded the Colour in Film conference in 2015/16. On the one hand, colour is indeed connected to physics and chemistry, but on the other, it also has to do with the brain, with perception and, of course, aesthetics.

The digitisation of archival images is a dominant current trend of course. I am concerned about the proliferation of digitally reworked, computer-coloured images that are misunderstood as historical documents. In times when access to historic film material is becoming easier, and more and more technical tools are available for manipulating images, even by amateurs, the door is opened to falsification of history.

One can and must also argue about the commercial processing of historical recordings. I’m thinking specifically of Peter Jackson and his First World War film “They Shall Not Grow Old”, which was shown in German cinemas in 2019. Jackson restored, coloured, cropped and converted historical silent film images from newsreels using 3D technology and then added dubbed commentaries by contemporary witnesses. “An authentic look at the First World War”, found SPIEGEL. Completely without entirely dismissing this work out of hand, I would strongly disagree with this assessment. Such an approach can also pose certain risks, as I discussed with my colleague Prof. Dr. Franziska Heller in an article for the online portal kinofenster.de, published by the Federal Agency for Civic Education.

And some things are simply unethical. The colouring of film footage from Auschwitz – that actually happened! To me this feels akin to the desecration of a grave for the purposes of ‘infotainment’.