[2] He was a friend of fellow Linceian Galileo Galilei and the German painters in Rome, Johann Rottenhammer and Adam Elsheimer.

Faber spent two months, enjoying the vigorous intellectual life of Naples with men such as Ferrante Imperato, Giambattista Della Porta, Fabio Colonna, Giulio Cesare Capaccio, Nicola Antonio Stigliola, Quinzio Bongiovanni, Mario Schipani, Marco Aurelio Severino and Brother Donato D'Eremita and learning about plants, botanical gardens and collections of rare objects.

Here he was a frequent visitor to the pharmacy of his friend the Dutch botanist Enrico Corvino at the sign of the Imperial Eagle in Montegiordano, where many of the city's artists and physicians gathered.

Corvino was to become a member of the Accademia dei Lincei in 1611, and Faber came to know a number of the men who were involved in its work, including Federico Cesi, its founder, Johann Schreck and Theophilus Müller.

Faber hoped to make him a gift of a telescope, but was unable to do so owing to the difficulties Galileo was experiencing in producing lenses of sufficiently high quality.

Nevertheless, he was able to use the visit to help foster academic projects in Germany, ensuring that the Bishop was given a number of books written by members of the Accademia, and a sample volume of Hernandez's Mexicanarum plantarum which Cesi had charged Schreck and Faber with editing.

In 1609 fellow Lincean Galileo developed a compound microscope with a convex and a concave lens, which he called the occhiolino, the "little eye".

[10][11] In 1608 Faber became a naturalised Roman by adopting the legal status of "civis romanus": on 19 August 1612, he married Maria Anna Hyrler, who was herself born in Rome to German parents.