Barberini had the first Campani telescope sent out of Italy, and he showed it around in Paris to win favor for Campani. Early on, Cassini became convinced that Campani's telescopes were better than Divini's. All of Cassini's discoveries were made with Campani telescopes. Because of Cassini, Campani's telescopes equipped the Royal Observatory in Paris. Bedini also lists the Kings of Poland, Spain, and France, and the Landgrave of Hesse as Campani's patrons.
Instruments See above.
Add that Campani ground lenses of up to about 150 feet in focal length. And he designed mountings to hold them, so that they could be used.