With so many choices of surveillance cameras in the market, it is very easy for a consumer to get overwhelmed and confused in choosing the right surveillance camera for their needs. Whether you are purchasing a security camera for a home, business or government application, there are some basic things that any purchaser should know in order to make a well informed decision. In this article we will cover the first of a series of topics to help educate someone that is researching the purchase of a surveillance system. The main topic for part one of this article series is camera resolution.



It is very important to understand what resolution means when shopping for a surveillance camera. CCTV (closed circuit television) cameras range in resolution from 330 TVL (television lines) to 600 TVL. For color resolution, CCTV cameras max out at 560 lines, however you can get black and white CCTV surveillance cameras in 600 TVL. IP surveillance cameras are now available in much higher resolution (up to 5 megapixels in resolution). What does this mean when planning a system?

In the United States, regular broadcast television (not high definition) displays 480 lines of resolution, so it is possible to purchase CCTV cameras that can capture equal to or greater resolution than television. Obviously the higher the resolution that you choose, the more detail you will see in your surveillance video. High definition television (HDTV) displays either 1080 or 720 lines of resolution depending on the channel and the type of HDTV that you have. In order to get higher resolution from surveillance cameras, the only choice is IP based megapixel cameras, which connect over an IP network instead of closed circuit. IP mega-pixel cameras are much more expensive than CCTV cameras. Prices for a quality CCTV camera range from $69 - $499. Mega-pixel cameras range from about $599 - $5000. For high end applications that demand ultra-high resolution megapixel cameras can capture surveillance video at more than twice the resolution of high definition television.

In my experience, some people that are shopping for a surveillance system have an unrealistic expectation for what a surveillance camera can capture (especially a CCTV camera). I will go in to more detail about lens size and types in the next article in this series but I must touch on it briefly now as it is so closely related to resolution when planning your system. For this example, we will use a 3.6mm lens which gives you about a 90 degree field of view outward from the lens. Some people think that if you take a 480 camera with a 3.6mm lens that you will be able to get a clear picture both of an object that is 20 feet away and an object that is 80 feet away. This is very far from the truth. While the 3.6mm lens will easily pick up the object in detail at 20 feet away, it cannot pick it up at 80 feet away also with the same 3.6mm lens. In order to pick up the object at the further distance, one must either use a larger lens that would make the image more zoomed in or use a high end megapixel camera that would allow the operator to zoom in digitally without distorting the picture. Digital zoom is possible with high end megapixel cameras, but not with normal resolution CCTV cameras. This will lead us into the next article in the series which will be about understanding and choosing the right lens.