  The 14 years old cameras of the H.E.S.S. 12-m telescopes have been upgraded
in 2015/2016, with the goals of reducing the system failure rate, reducing the
dead time and improving the overall performance of the array. This conference
contribution describes the various tests that were carried out on the cameras
and their sub-components both in the lab and on site. It also gives an overview
of the commissioning and calibration procedures adopted during and after the
installation, including e.g. flat-fielding and trigger threshold scans.
Finally, it reports in detail about the overall performance of the four new
H.E.S.S. I cameras, using very recent data.
