Since 1990, de Roos participated in numerous national and international photo exhibitions, in Munich, Leipzig, Duisburg, Amsterdam, Zürich, Vienna and Madrid, among others.
Between 2000 and 2008, he created the Rodin-Web, the world's largest academic Website focusing on the life and works of the French sculptor Auguste Rodin.
In 2001, he was a speaker at the conference "Rodin and the Original" at the Royal Ontario Museum in Toronto and initiated the 3D-scanning of original Rodin plasters in over 20 European art museums during a seven year project. An intermediate report about the scanning and comparison of different examples of Rodin's Thinker sculpture was published by Linkoeping University Elecronic Press in December 2004 (see www.ep.liu.se/ea/cis/2004/002).
In dialogue with the Dutch author Frans Gilson, de Roos engaged in research about the concealed identity of Prof. van Helsing, published in the Dutch literary magazine De Parelduiker in October 2012. He is currently planning to publish a book about Van Helsing, hypnotism and psychical research in the Victorian Age.
Other current book projects include photographed versions of Sheridan le Fanu’s Carmilla, Edgar A. Poe’s Short Stories, Lewis Carroll’s Alice in Wonderland, Tschaikowsky’s Swan Lake ballet, Brother Grimm’s Fairy Tales, Boccaccio’s Decamerone and Dante’s Inferno.