With all due respect, amperage and voltage are separate issues. the power supply will supply 13.8 volts to as many camera's as I hook up to it until i exceed the 10 amp rating of the power supply... at that point it would pop the circuit breaker. My camera's draw less than an amp each, so i have plenty of capacity for my 8 camera's.
The big thing I am worried about it the 13.8 volts. I could investigate turning the voltage down on the power supply to 12 volts, but i am not sure that is necessary.
That being said, I know radio equipment, not security camera's. Lowering the voltage increases current (amps) and that is usually not a good thing. More current = more heat which can lead to burning the camera up, or if your lucky just some unusual behavior.
My concern is that a little more voltage could be an issue as well. That's the answer I'm looking for. Radio equipment is generally OK from 11.2 all the way up to 14.6 volts, which is the range possible in todays autos.