  The next generation of Cherenkov telescope cameras feature Silicon Photo
Multipliers (SiPM), which can guarantee excellent performance and allow for
observation also under moonlight, increasing duty-cycle and therefore the
physics reach. A 4 m-diameter Davies-Cotton prototype telescope with a 9-degree
optical FoV and a 1296-pixel SiPM camera, has been designed to meet the
requirements of the next generation of ground-based gamma-ray observatories at
the highest energies.
  The large-scale production of the telescopes for array deployment has
required the development of a fully automated calibration strategy which relies
on a dedicated hardware, the Camera Test Setup (CTS). For each camera pixel,
the CTS is equipped with two LEDs, one operated in pulsed mode to reproduce
signal and one in continuous mode to reproduce night-sky background.
  In this contribution we will present the camera calibration strategy, from
the laboratory measurement to the on-site monitoring with emphasis on the
results obtained with the first camera prototype. In addition, key performances
such as charge resolution, time resolution and trigger efficiencies and their
degradation with increasing night-sky background level will be presented.
