I have a few, the best one is a "Wildgame" i bought through a gun shop at about $260 + funny enough. Battery life on Wildgame is up to 6 months from trial, I just test batteries each time I check the sd card. This one has an audible/visual test. (most modern ones do now)
I have the oldest one from Jaycar that played up after a heavy rain storm and the pictures for the next week where misty, you could still see but I was annoyed as the camera was about $300, supposed to be water resistant (not), it was big and bulky , took 4 x "D" cells and 3 "C" cells, heavy on the juice. they don't sell them any more.
The Acorn off eBay is the most efficient for price so far, these are small, good and easy to hide, they have iPhone connectivity and alert, only if you are in a service area, you can get other systems that connect to your smart phone further away from civilisation but they are more expensive.
Acorn with energisers does not last as long and I have had problems with burst batteries (from heat I assume), Duracell will last for months and heat does not seem to affect them as much,that said I should have shares in Duracell for the amount of batteries I use but it's cheap insurance, or you can use the solar panel for a continuous power supply but is harder to hide.
Another miner I know in a populated mining area has one camera only and just has a sign above it "SMILE". He hasn't had any problems since, but I think it's foolish to have only one. For a grand you can get up to 6 cameras these days. Signage, one obvious camera, other camera hidden near that to take in the field of the first, as many cameras as you need to cover entrances, exits, camps, machinery, workings and tracks.
Check often, being there is best, get the word out there are cameras.
I had a few semi-honest visitors when present before I had cameras, since word has got around and I have not had a problem. Map of lease area and clearly marked boundaries is a must as well. Good relations with the property owner helps, keep them informed when coming and going, fill them in on stock movements, vehicle movements, water, rainfall etc,it's all appreciated.
Most of the multi camera security systems you would use in your home use 12 volts after the transformer, you can get an electrician to wire it up for solar and 12v battery, they are low current draw but are limited by the cables, more expensive ones use wifi so each camera needs a good battery type that will last in the heating and wet weather.
Heaps of options out there. If your like me, the area is remote so stand alone works best, cameras that transmit to a central collector use quite a bit of power so battery life is compromised.
You still get people that think it's okay to pick up stuff off someone else lease, it's not, as far as i'm concerned it's theft, I have signs to that effect, even if the Crown gets it you are the one loosing out.
Some illegal prospectors have meet with foul play in the past , as they have done in the past in W.A.
It's good to keep the cameras on while you are there as well, just in case.
I also have a spot 3 tracker which I think is worth looking into for personal security, a good investment for $200 per year, there are other brands that can send texts as well. Safety first!
I hope this helps.