It's that simple, security camera placement is about Location, Location, Location. The devil is incorporated in the details and the details determine in which a camera should be placed. All too often a security camera is placed to cover as much real estate as you possibly can and that is the wrong approach. A CCTV or Surveillance System should be just that, a system. Each camera should play a vital role within the complete system, like a single instrument within an orchestra, alone they're nice, but when combined they magnify each other's performance.
Within my humble opinion, the most important camera inside a complete CCTV product is the gotcha camera. This home security camera should provide you with the same image as the culprits mug shot will once the police take his picture, that is to say, super close-up. Often the best location for this camera is appropriate behind the register. Obviously every store has one there but they usually try and cover the entire front counter. Huge opportunity loss! The gotcha camera ought to be at eye level at the front of the customer (actually slightly aside so that the salesperson doesn't block the look). A could be robber would think twice after staring in to the eye of the camera. This home security camera should be such a tight shot that you simply only have a few feet on both sides of the check out. It is the money shot, the one that will place the robber into that mug shot I spoke of earlier.
If you're doing a home surveillance system then your gotcha camera could be at eye level in front door. Since 70% of all break-ins occur via a door, and many of them are with the front door, this is your money shot. Whether or not the burglar doesn't break-in in front door he'll almost always ring the door bell to see if anyone is home. Once more, after looking into the eye of the camera he'll probably visit another house. Another good location for the gotcha home security camera is at a gate. Most burglars will use the easiest method to enter into the back yard and if you have a fence, that might be the gate. You shouldn't be tempted to have an image of the entire fence, you would like just the gate, so you can get that sharp picture which will put him on the 11:00 news. (10:00 Central time)
Not every security camera should be the super close-up. This is when the concept of an entire system is available in. Like in any movie you'll need a camera to set the stage. That wide angle shot that sets the scene in every TV sitcom, which makes you think they live in that house. You can cover a lot of ground with this particular camera, even though you would not be in a position to identify the individual, that's the job of the gotcha camera. This surveillance camera covers a sizable area to try and catch the bad guy in the act. It may be a parking lot or a backyard. By itself if might have little benefit, but because part of a system it plays a vital role. you might not be able to find out the intruder, but you'll have the best chance of catching him red handed. Inside a parking lot it will give you an idea of the kind of car he drives and just what direction he was going when he left the parking area. In a store you might see two criminals working together and see which camera they're walking before.
The last location may be the security camera that fits in approximately the super close-up, and also the stage setting wide angle camera. Its role is for high priority locations. Maybe in which you have expensive merchandise or perhaps a trouble spot where you have had shop lifting issues before. It may be the very reason you decide to get a CCTV system. In the home it might be in an area in which you keep valuables. You will want to cover just as much real estate as possible while still being able to identify the culprit. The important thing to this camera location is to not try and canopy so much area that your can't identify the person ripping you off.
Leading us to facial recognition. This priority camera must incorporate facial recognition. Which means you must be able to identify the person who is taking food out of the mouths or perhaps your children and stealing the Gifts of your Grandchildren from beneath your tree (both figuratively and physically). The FBI has come up with a rule of thumb of ten heads. Look at the image on the monitor and picture stacking the heads along with each other like on the totem pole. Should you only make it half way up your screen by the time you count ten heads, then the face will be too small to have an identifiable image. Anything less then ten is good as long as you balance the real estate you want to cover using the size of the face area.
To sum up a perfect surveillance or CCTV system, you will need at least one money shot camera (your gotcha scum-bag camera), at least one stage setting camera (your wide shot camera), and as many priority (high risk area) video security cameras as needed. This will depend on the size the store and also the merchandise you're trying to cover.
One last thing I have to cover, is the monitor. After putting together a killer system, don't go and mess it up by putting the monitor in an area where customers can see it. A robber will be looking for blind spots, if he aren't able to find any he'll wear a mask. You might have a camera super tight for the gotcha shot, but all of the shop lifter sees is really a camera and he doesn't want to obtain picked up. If he thinks he's on camera he won't try anything. Like a poker player, never show you until you need to.