1. Not having enough cameras
Recently a donut shop in Massachusetts was robbed at gun point. They had good quality cameras – but unfortunately they did not have enough of them. They had one camera focused on the cash register and another camera focused on the clerk, among others. What they didn’t have however was a camera focused on the customer at the counter so they didn’t capture a good image of the criminal. Poor camera system design let that crook get away.
Solution: Make sure you have all your bases covered in your design. Some standard camera views to consider are entries and exits, cash registers, counters, hallways, stairways, driveways, garage doors, parking lots, loading docks, and each exterior side of the building. After you install the system, review the camera system design again to determine if there are any other blind spots that need to be covered.
2. Not using the correct cameras for the application
One size definitely does not fit all when it comes to security cameras. Each camera in your application should be specified individually. A camera that you use outdoors to cover your parking lot needs to be much different than the one that you use to cover your front door. Wide-angle cameras are great for covering broad areas but do not provide close-up detail. Conversely, cameras that provide good close-up detail do not cover a wide-angle of view. So for each camera position in your security camera system, you need to choose which requirement is more important. If you need close-up detail you may need more cameras to cover the area. Also consider if infrared (nighttime viewing) is going to be needed at that location and if so, how much infrared distance is necessary.
Solution: Make sure you specify each camera at your site individually. If the priority for wide-area vs. detail is not immediately obvious, then consider a varifocal camera which will allow you to adjust the focal distance after you install it.
3. Not having a DVR with enough camera inputs
It’s very common to put in a security camera system with a certain number of cameras and then later realize that there are other views that need to be covered with additional cameras. So when specifying a camera system make sure that your DVR has enough cameras inputs to not only handle the number of cameras that you initially intend to install but also some extra slots to allow for future growth. Most DVRs cannot be expanded to allow for additional camera inputs, and for those that do allow for expansion it can be quite expensive so your best bet is to specify extra camera inputs up front.
Solution: When specifying your DVR, allow for twice as many camera inputs as you think you need. The additional cost is minimal and it’s very likely that you will use this extra capacity in the future.
4. Not having enough storage space on the DVR
When the storage space on a DVR gets full, the DVR will start recording over the oldest video on the hard drive(s). The more cameras and microphones that you have hooked up to your DVR the quicker that storage space will be used up. So the general idea is to figure out how far back you might need to search for a particular incident. The problem is that you may not be immediately aware of when something happens. For example, if you are on vacation you may not be aware that something went missing or got damaged until you get back. These days surveillance video is used very often in liability cases which may not come to your attention for weeks or months. Some people turn down their recording frame rate or image quality to save on hard drive space but this is counter-productive. If you ever need to reference the video you will want the best quality possible.
Solution: For businesses we recommend planning for at least 60 days of recorded video on their DVR. For residential installations we recommend at least 30 days of recorded video, or higher if liability is a concern. A modern DVR (H.264 compression, real-time recording rate) will use approximately 5 to 7 gigabytes of hard drive space per camera, per day. Therefore, a 4 camera DVR with a 500 gig hard drive can store about 18 to 24 days of recorded video. A 16 camera DVR would require 4 times that amount (2 Terabytes) to store that much. You can set up record time scheduling and motion detection (if appropriate) to extend the recording capacity of the DVR – but don’t turn down the image quality or the recording frame rate.
5. Using cheap cable to wire your security camera system
Some people try to save money by going with cheaper cable (like Cat5 or twisted pair) but what they save up front they will make up for later by needing to purchase amplifiers, ground loop isolators and video baluns. High quality cable is especially important for infrared cameras and for longer camera runs to the DVR. Poor quality cable can cause problems such as image interference, rolling lines, intermittent image loss, and damage to the camera. A camera might have a great picture during the day but look terrible at night (when infrared kicks in).
Solution: Use top quality 95% copper braid RG59 Siamese cable which combines the video coax cable with the power wires in the same jacket. Only use plug and play cable or other cheaper wiring solutions for short runs and with no long-distance infrared cameras.