What you have posted does not make any sense to me. What are you trying to achieve?
How do you know that you need a voltage to trigger the camera? Most cameras with external triggers simply require a contact closure.
If your camera does require a voltage, how much current does the camera trigger circuitry draw? If it is small, a battery would probably work (e.g. a 3.3 V coin cell). It seems ridiculous to use a 14.8 V to 3.6 V stepdown regulator just to provide a signal!
[quote]Unfortunately, the camera manufacturer doesn’t provide info on how much current the Schmitt trigger draws but estimates are 20-30mA.[/quote] That also seems unreasonable, but I suspect that the 20-30 mA figure comes from the LED designed into the circuit, which you plan to remove. It is trivial to measure the actual current passing through the camera input. Even if 20 mA, a couple of AA batteries would last for a hundred hours of continuous operation.
Without more information, it is impossible to say what the 100 ohm resistor and the 10 uF capacitor are supposed to be doing.