  We present the photometric characterization of the four iXon Ultra 888 CCD
cameras of the SPARC4 instrument, which will be installed on the 1.6 m
telescope of the Pico dos Dias Observatory in Brazil. We applied experimental
methodologies for a systematic characterization of the read noise, electronic
gain, dark current, and quantum efficiency of the CCDs. We have analyzed the
statistical distribution of the read noise, and also its spatial gradient and
temporal variability, where we obtained an average value of the read noise of
6.33 electrons. We applied the Janesick method to determine the electronic
gain, where we obtained an average value of 3.35 e-/ADU. We have also obtained
an average dark current of 0.00014 e-/pix/s for CCD internal temperature of -70
oC. We have inspected the dependency of the dark current with temperature and
the spatial distribution of the dark current, where we found a variable profile
in the CCD 9917. We developed an experiment using a bench mounted monochromator
to obtain the spectral dependency of the quantum efficiency in the spectral
range between 350 nm and 1100 nm, where we measured the quantum efficiency for
each camera. The camera 9915 presents the highest quantum efficiency of 95.8 %.
Our results are compared with those from the manufacturer. These experiments
allow us to diagnose the performance of these CCD cameras, an important
sub-system of the SPARC4 instrument. It also provides a systematic way for
monitoring the aging of the CCDs.
