Opto activated flash trigger

Hey guys!

I'm quite new to arduino and I'm still learning. I was planning on a next project but I'm not completely sure if it is feasible. So, the idea is:

I would like that the arduino reads the value of a photoresistor determining a baseline. Then, if the value of it goes above the threshold, it would close a circuit between an input and an output. The idea is to have a photo activated trigger for a flash that doesn't trigger with normal light conditions. The flash should trigger by closing the circuit because the input will be connected to one pin from the flash and output to the other which to be triggered need to be shorted for a very short moment.

Would it be possible? Of course, if it works I would like to include other mods, like sound activated, or repeats, etcc...

Many thanks in advance!

Totally possible. But I would not use a light-dependent resistor. It will be too slow.

A phototransistor or photodiode will work faster. Buy one on a breakout board from Sparkfun or Adafruit. Something like the TEMT6000