Output signal splitter

Just a question!

I'm going to use Aurdino as wired remote shutter control for ca 20 cameras (f.e. GitUp action camera with PWM shutter triggering). What is easiest way to multiply one Aurdino output digital signal to many signals, as I want to trigger all cameras at the same time? I do not know what input currency for camera is, but suppose that 40mA (what is max output currency for Aurdino pin) is not enough for 20 cameras.

amplify it with a transistor, then use wire to "split" it.

Don't know what PMW has to do with it... Aren't they just edge triggered?