Using a transistor to control a pull-down switch
You have Q1's emitter and collector swapped. It might work in that configuration but it's not the right or most reliable way.







simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. NPN transistor ORed with internal switch.

I've redrawn the circuit in a more conventional fashion. Positive voltages are to the top, grounds at the bottom and logical control flow from left to right.

The camera will have a pull-up resistor on the input and SW1 pulls it to ground. Your Q1 will do the same thing.