The collection consists mostly of photographs. They cover various subject: processions, pilgrimages, ecclesiastical ceremonies, Boy Scouts, the labour movement, politics, health care, missions, the university and student clubs, to name but a few.

An important part of the photographs in this collection comes from the archives of catholic institutions and from private individuals. Substantial institute archives come from – among others – the KRO, the Catholic People’s Party, the Catholic Labour Movement/the Dutch Catholic Trade Union, newspaper De Volkskrant, the Saint Vincentius Association and the Eighth of May Movement.
Included among the personal archives are those of J.A. Alberdingk Thijm (1820-1889), A.M.A.J. Ariëns (1860-1928), J.M.L.T.Cals (1914-1971) and A.A.M. van Agt (*1931).

The collection also contains photographs from donations and legacies. A large collection of picture postcards of Dutch church buildings (both interiors and exteriors) for instance comes from the collection of a Capuchin monk.