The archive primarily contains a collection of photographs, a fascinating cameo of Byzantine art, consisting of 350 negatives personally taken by the art historian Sergio Bettini (1905-1986) during his many trips to Istanbul and the former provinces of the Empire of Constantinople from 1934 to 1940, financed by the Fondazione Giorgio Cini. As evidenced by a letter addressed to Professor Anti, dated 31 August 1955, and now in the archive of the Fondazione Cini Institute of Art History, this sponsorship was not only for the purpose of funding the photographic and film campaigns conducted by Bettini with his Rolleiflex and Bolex super 8 cameras. He was also asked to contact professional photographers, who over the years would enrich the photographic collections of the Institute of Art History, as in the case of Pericles Papachatzidakis.

The photographic collection mainly documents the architectural and monumental heritage of Istanbul and Greece, with a large number of urban views, and the islands of the Aegean and Albania. For two years (1931-33), at the request of the Regia Legazione d'Italia in Tirana, Bettini was responsible for carrying out research ahead of the creation of a photographic collection of Venetian monuments in Albania.

The negatives, which provided the same number of positives mounted on paper and inserted in the topographic section of the archive, show the wear and tear of time and rather advanced forms of decay. Stored in paper envelopes and inventoried, they are kept in special drawers reserved for negatives in the Fondazione Giorgio Cini.

The Bettini photographic collection is completed by seven extraordinary photo albums, entirely devoted to the monumental heritage of Istanbul, containing a total of 197 photographs by the painter and photographer W. Sender, dated 1925-1928. A further two smaller albums compiled in the same years with 12 photographs feature the basilica of Hagia Sophia and the church of the Holy Saviour in Chora (Kariye Camii,) in Istanbul, respectively.

The Bettini Archive includes manuscript annotations and typed drafts of his publications, while a documentary section is linked to Sergio Bettini's studies and contacts with numerous scholars and collaborators at the Fondazione Cini Institute of Art History, and principally the first director, his teacher Giuseppe Fiocco.