My current setup-
4 IP cameras (http://wiki.linuxmce.org/index.php/EasyN_FS-603A-M106_IP_Camera
). These are pretty cheap no-name branders but have served me well so far as I learn the intricacies of IP cameras.
I have setup one camera to watch the gate to my property- this allows me to see who's there when the intercom bell rings and to control the opening and closing without having to peer out of a window. Currently gate open and close is via remote and/or intercom button, not connected to lmce but that will come ;-) This is useful already, though, because viewing via mobile device (phone, tablet) means when I let people come in I can watch and ensure no-one unwanted sneaks in afterward and the dogs don't run out into the road.
This was my first cam and to power it I had to put an electrical socket in the ceiling. That was no fun - mucking about in the dark with a head torch while the power was off. But it's there now. Network cable and 12v power supply cable passes through a 16mm hole drilled through the wall and all joins to the camera sockets (RJ45) and 12v connector in a neat little electrical box I mounted to the wall just above the cam. To reboot I have to get physical access to the cam or power off the circuit-breaker for the whole set of wall sockets.
After the gatecam, I decided for permiter security, rather than looking outward from the house, it makes more sense to look at the house from the outside. For a couple of reasons. Firstly, looking outward naturally looks beyond your boundaries - to the road, the neighbours etc and you aren't interested (well, maybe you are, but not for motion detection surely) in what's going on there. Secondly, unless you get a really wide angle lens, you would need hundreds of outward looking cameras to cover the area.
So I've angled the remaining cameras to try to cover all the windows and doors along the house perimeter.
We have a nice boring rectangular house so one cam can cover more or less the whole front of the house, obviously losing detail as you get further along. I have two under the eaves of the house itself looking along the wall and two mounted away from the house looking onto it- one on the garage (can't remember what Americans call a garage) and one on a telephone pole. Two of the four are powered from the mains via the 12v powersupply that comes with the cam and the other two are POE.
The POE is an absolute pleasure. I have a POE Gig switch that injects the 12v and then individual splitters at the camera end that split off the 12v at the camera side. The one under the eaves is protected from the weather so I just screwed it to a rafter and neatened the cables with cable ties. The one on the telephone pole I put in an external electrical box along with the all the other connectors. Nice and neat. Great thing about the POE as well is you can depower the camera by unplugging it at the network switch.
All 4 plug into my external network - ie between my ADSL router and my Core's external NIC. So they are firewalled from the internet by the ADSL router firewall and therefore have private IP addresses - 192.168.x.x but aren't strictly DCE devices. I use my ADSL router to assign the same IP to them every time based on MAC address so I can easily link to them as devices on LMCE or with zoneminder or just connect to them with a web browser on my home network. Also use port-forwarding through the router to provide external (internet access).
I've deleted my motion-wrapper devices for reasons above - it just adds overhead to the network and to the camera if motion is trying to suck frames from them along with zoneminder but will re-instate them as basic cameras at some stage so I can just watch them from a media director when I need to.
I have a separate zoneminder installation currently on an old hp6410b laptop running fedora 17. That is watching all 4 cameras and recording motion events. Still tweaking the settings there, hope to get to a point where I have very few "false" alarms, especially at night, so that I can ultimately use it to raise a real alarm if anything's detected. False alarm frequency at night has to be down to 1 every 2 months or fewer before you let it wake you up, in my opinion.
The zoneminder machine serves up a montage of screens which I watch on the laptop - because at the moment it's installed on the kitchen counter but ultimately it should be tucked away somewhere. It's not a fantastic interface but it works ok.
My cheap 7" tablet, running IP Camera Viewer. This is an android app and works really well. My Android phone running the same app.
These cameras provide their own IR illumination via 48 IR LEDs that come on courtesy of a built-in light sensor. They illuminate quite effectively for around 20m so you get quite a bit of detail at night, even in the dark. Unfortunately, they also seem to attrack moths and bugs which like to fly around in front of the lense and create rapid, dramatic motion events. An option would be to disable the camera's illumination and get an IR LED floodlight to illuminate the area separately. Then perhaps the moths would fly in front of that and not the lens. Some success can be had by filtering out events that trigger fewer than 2 frames - moths are very quick when they're that close... and non-ninja-trained intruders usually trigger more frames.
* IP Cam frame rate is definitely lower than analog cameras. Videos tend to be a bit more jerky than analog ones from what I've seen. Apparently, though, individual frames will usually be better quality so useful for court-cases etc.
* When all is ok, it works neatly but there are many minor glitches related to network issues... may be just my setup but it's there. WiFi for one thing- my router gets itself in a knot every so often (like once a day) and won't hand out new IPs it seems. So when wireless devices try to connect they can't.... annoying when you want to quickly check the cams from the tablet. Still trying to get to the bottom of this. One option is fixed addresses rather than DHCP which may help - leave DHCP for visitors who want to use the network. But I'd like to know why it's a problem first.
* Field of view of cameras is far more limited than you realise - apparently a 6mm lens is roughly the same "zoom" as your eyes but your eyes take in much much more in a scene. You can get shorter lenses which cover more but obviously you then sacrifice detail, given the same ccd size so it becomes a trade-off. Increase the ccd size and you increase your bandwidth requirement, memory and processor and storage requirement.
* Motion detection out of doors is a major challenge. I can see why all the security companies are reluctant to install outdoor detectors and link them to the armed-response units... there are so many false alarms.
PIR vs Camera-
This is mostly speculation - along with my other musings... so I'm happy for correction here by someone more knowledgeable. Essentially they're much the same thing... the PIR is just sensing in a different wavelength (invisible light) and generally at a much much lower resolution. They tend to use those fresno type lenses which is a crude wide-angle lens and their "ccd" has dramatically fewer "pixels". The advantage of all this is that it's way cheaper (lower res, simpler electronics) and they tend to "look" for a shorter distance so facing them toward the road or the neighbours is less of an issue because at that range, you'd need a very large part of the scene to change to trigger motion detection. So I guess something similar could be achieved with an outward looking cam with a wide angle lens. Then you could define motion minima that only trigger when the object is close enough to be big enough. The PIR is useful too in that the IR range doens't require illumination and usually humans are warmer than their surrounds which provides nice "human" detection. Works nicely indoors but outdoors again is a lottery. Also quite easy to mask - I've walked past all our indoor PIRs carrying a bedsheet in front of me and fooled them all by shielding my heat signature. Cams would be much more difficult to trick.
Fact is, everything struggles outdoors because the environment is so difficult to control. All systems will require some tweaking and trade offs between sensitivity and false alarms. The big plus with a camera is the video record! This gives you two things-
1. Peace of mind - if you *are* woken at 3am by an alarm, you can at least check the footage and know for sure whether it was a real threat or a false alarm. This is huge- without normal outdoor beams/passives you have no idea and feel compelled to sneak out into the garden in your boxer shorts to verify... which is completely stupid but the natural tendancy.
2. Ability to tweak the settings based on real events - you can review the footage that triggered the alarm, look at the stats of the alarm frames and adjust your settings to potentially eliminate it. Trying to tweak other sensors is a real hit and miss affair.
Hope that was useful reading for someone and not too off-topic for LMCE. Ultimately I want to integrate a lot more with events / security / automation / MD notification etc so I feel it is relevant.