The collection of fonds includes some 40 archives, fonds and large ensembles of Belgian photographers and companies from the 19th century to the present day. All in all, these photographic and paper archives comprise almost 3 million items. This makes it the largest collection of the FOMU in terms of size. The collection provides a good overview of photographic practice in Belgium, because it involves fonds from both professional and amateur photographers. Its content, size and nationality distinguish it from other collections in Belgium and abroad.
The collection took shape through donations, long-term loans and purchases. The most extensive fonds include the photo archives of Herman Selleslags and his father Rik Selleslags, which the FOMU has received on permanent loan, and the Historical Agfa-Gevaert Archives. Examples of some other fonds are those of Willy Kessels, Suzy Embo and Filip Tas.