Don't know if this pertains to your interests but I've built a few solinoid trig cams [12v door locks run on 6v]and bought the first commerial one I ever saw. They are way too noisy for deer ...the plunger fires and thier a blur or gone totally. I have good luck running my slr's and powerflashes on bird scenes with plungers but there's no way I leave that stuff out like a trail cam....stick to the electronic shutter even if you gotta go buy a new cam...yoteee'
I used the Jameco 12v solenoid listed on Jesse's site in my game camera. The solenoid makes a lot less noise than the camera does. I put it inside a 30 cal ammo can and it doesn't seem to bother the deer.
Eventually, I'm going to put together another camera using the same setup.