Filed under: Beginning CCTV, CCTV Articles, CCTV Glossary, General Technology, Guides, IP Cameras, Security Camera
When shopping for a new CCTV System, don’t be confused by the plethora of acronyms describing cameras and DVRs! Keep a few key pointers in mind:
1.) FPS (or Frame Rate): This spec informs you of how many frames-per-second the camera or DVR runs at. The max each channel can record at is 30 frames per second. 30 FPS is considered to be live motion as if you were watching it happen with your own eyes. Keep 30 FPS in mind when you are shopping for a DVR, as you’ll notice that some DVR units mention things like, “8 Channel DVR with 240FPS.” This means the max recording ability is 240 across all the capable channels. Take the 240 and divide it by its 8 channels, and you’ll get 30 FPS per Channel. Some DVR units will not always allow you to view all channels at the full 30 FPS. Some DVRs will mention “16 Channel DVR with 120FPS;” this means the system is capable of up to 16 cameras, but can only share 120 frames across all the channels. To get you per camera frame rate take the 120 and divide by 16, this will give you 7.5FPS. With this kind of low frame rate, you can expect the video to be a little more intermittent, and it may not be as fluid as videos with a higher frame rate.
2.) TVL (or Television Lines): TVL is a number you typically see only on Analog cameras, and it tells you the resolution of a given camera. Some cameras may have resolutions as low as 420 TVL, while others may range up in the 600-700 TVL area. Naturally, the higher the number, the more clear and crisp the resolution and picture will be. At the moment, the highest an analog camera’s resolution can go is 700 TVL. This spec is one of the most important things to consider when picking the right camera.
3.) MP (or Megapixel): This is the resolution of an IP (Internet Protocol)-based or network-based camera. Instead of running at the traditional TVL measurement, IP cameras use the Megapixel format to illustrate the resolution of any given camera: 1MP, 1.3MP, 2MP, 3MP, 4MP, and 5 MP. Cameras do have the ability to go higher than 5 MP, but it’s not a proven technology yet, and it’s much more reliable to stick around the 5MP area to keep a good resolution to FPS ratio. As you increase the camera’s MP, you decrease the frame rate and vice- versa. Any camera going over the 5MP area will not be capable of producing a significant frame rate, making the camera nearly unusable, as the video will appear as more of a slideshow than actual movement. A 2MP on the IP camera side can equal 4 standard analog camera images combined. Not to mention IP cameras usually come with some really sophisticated bonus features.