Löser was born in 1962 in Karl-Marx-Stadt (today Chemnitz). From 1990-95 he studied at the Film School in Potsdam-Babelsberg. Since 1990, he has been the program director for the BrotfabrikKino in Berlin. In 1992 he also began working as a freelance film critic (taz, Berliner Zeitung, film-dienst). The same year, he was honored with the Art Award from the Berlin Academy of Art. In 1996, he became the founding director of the collection ex.oriente.lux (Experimental Film Archive East 1976-1989) and also published the book Counter-images – cinematic subversion in the GDR. He received a scholarship from the DEFA Foundation in 2001. In 2004, he curated the exhibition Berlin – Moscow / Moscow – Berlin 1950 to 2000 (Gropius Bau). He received a scholarship from 2005-2007 from the Foundation for the Study of the SED dictatorship. In 2009, he curated the film series, Winter adé – Filmische Vorboten der Wende (Berlinale 2009). In 2008, he published “counter-images,” a compilation DVD that was released in Germany and the USA. In 2009, he produced the documentary Claiming the Space – Ways of Independent Art Exhibitions in the GDR (with Jakobine Motz). He completed his doctoral thesis at the School for Film and Television in Potsdam-Babelsberg, with a dissertation on GDR art films.