Why are you doing this?
Why install a surveillance system anyway? Obviously this is a personal matter whereby you are balancing intruder detection, identification, general property surveillance, and more importantly some way to make you feel safer in your own home or business.
So let’s start with a quick overview of the systems available and how they can fit together to accomplish your goals. As we run through them, consider the things you want to accomplish:
Obvious security system in place to deter criminal activity
Audible alarm to startle intruders and get them to leave
Instant alert to you wherever you might be
Inform authorities on an intrusion event
General home observation â€“ see who is driving up, who is ringing doorbell, view kids in backyard
Clandestine surveillance â€“ baby sitter, who is sneaking into the fridge etcâ€¦
Each of these has different requirements, different camera and DVR needs, and different costs of implementation â€“ one system does NOT fit all. Some needs actually require multiple systems to accomplish your goals.
Alarm Systems :
A perimeter alarm system is most definitely the first line of defense and should not be overlooked. A video surveillance system can provide some alarm signals, but instant activation on a door opening or window breaking is accomplished much more reliably by a traditional perimeter alarm system. We will not cover the details of those here, but it should be noted that both self-install wireless and wired systems are straightforward to install and there are many companies that will install on for free as long as you sign a monitoring contract. Mine was installed during original construction by Ultimate Electronics.
Monitoring: Should I pay for it?
This is hugely controversial, but my belief is that it is a waste of money. If an alarm goes off, the remote operator has no way to know if it is a valid alarm or not and after a quick attempt to contact you they simply call the police. Sounds good, but false alarms normally carry a bill from your city for $50 or more each and these impersonal alarm calls do not normally receive top priority. An alternative is a voice dialer â€“ connecting one into your system automatically dials your cell (and up to 3 others depending on model) to let you know there has been a trip event. If you have a home surveillance system set up, you can flip open your phone, see that there is, in fact, an intruder and place a personal call saying you can see an intruder in your home. That gets an immediate police response. Be sure to check with your insurance company to make sure your planned system counts in their books as a monitored system and will get you the discount.
The Security DVR: A unique combination of technologies
Historically, these were tape machines which took time lapse (a picture every few seconds) to stretch out recording time from a few hours to a few days or more. Problem was that someone had to remember to change the tape, quality was pretty bad, they were on-site viewing only, and typically you would only get a frame or two of an intruder. On top of all that, if you didn’t know when an intrusion happened you were stuck looking through hours and hours of video to find what you wanted.
Putting multiple cameras on a recorder normally involved putting a “quad tiler” in-between the cameras and the DVR â€“ allowing you to put 4 or more cameras on a single recorder.
More recent video compression and microcontroller/processor technologies take the concept to a new level and build in features that now make home self installation a logic conclusion.
A good selection of DVRs can be found at www.amperordirect.com â€“ take a look through the options to see what is available. You should have a pretty good idea of the options before you dive in too much farther.
Tivo vs. Security DVR â€“ No they are not the same thing
The most common colloquial term of DVR refers to a device for recording your favorite TV shows. They typically include scheduling capability, an NTSC or ATSC tuner, and usually the capability to control an external cable or satellite box. It is difficult or impossible to adapt any of these to a security application. Simply put, they are not designed for long term continuous recording or recognizing on-screen motion. Maybe that seems obvious, but the similar names do tend to confuse the issue.
PC Based vs. Stand Alone Security DVRs
It should be noted that there is a corresponding whitepaper on building your own DVR out of an old PC. (www.bocsco.com/dvr) Definitely a great weekend project. But, please don’t do it for a security application. There are, in fact, add-in cards to upgrade a computer to be a security DVR, and there are some great off-the-shelf software packages, but typically it is not worth the trouble. Unless you start with a good (and solid) PC, top of the line equipment, and a LOT of knowhow, you will end up with something not as reliable as a stand-alone unit. Given the current pricing of stand-alone DVRs, there is no good reason to attempt to build one.
There are commercially available PC based DVRs available, however, and there are some good reasons to consider one if you fall into one of a few specific categories. If you have more than 16 cameras, a PC based DVR is more expandable. If you are trying to integrate home automation, alarm, and security DVR into the same device, a PC is the best platform. Or, if you are just an experimenter and not as concerned with long term reliability, by all means, give it a shot.
To Be Continued in Part 2 of 2:
DVR features and Input/Outputs: This is a big section â€“
Whole-Home Connectivity: I want to see my security cameras anywhere in my home
Things to check before you buy (or very quickly thereafter in case you decide to return the system):