The most recent upgrade in CCTV is the HD-SDI camera, the letters stand for High Definition Serial Digital Interface. The image resolution produced by HD-SDI cameras is up to 5X greater then a standard analog CCTV camera. It is the same quality image as HD TV and the familiar Blu-ray images. When viewing images, one of the main advantages of HD-SDI technology is that there is absolutely no loss of image information and no latency which does exist with IP network cameras. Another advantage of the HD-SDI camera is most use progressive scan technology instead of image interlace used in standard cctv cameras so motion images will have little or no image blur which may be critical in identification as shown below.

Left JPEG image (704x576 pixels ) is from an analog camera using interlaced scanning. Right JPEG image (640x480 pixels) is from an Axis digital camera using progressive scan technology. The type of lens and speed of the car at 15 mph was the same.

  These newer HD cameras can also use the same RG59 or RG6 cables as standard security cameras so installation is as simple as just replacing the camera and there is no networking knowledge needed. They will however need HD-SDI compatible DVRs since standard security DVRs will not have the circuitry to display the HD images. The HD cameras come in two different resolutions 720p and full 1080p. As with standard security cameras the cost for the higher 1080p version will be more and will provide the best image but the 720p cameras are still a great improvement over standard D1 security cameras. Another benefit is the HD camera's 16:9 aspect ratio will also provide a wider field of view than standard camera's 4:3 aspect ratio when using the same lens and image sensor size.

  As with any security camera not all HD cameras available produce the same image even though many look the same. Differences in lens quality, brand of image sensor, type of DSP used (digital signal processing) and low light ability can affect overall image quality. Even cameras with infrared LEDs can vary in the clarity of images they produce in darkness or nighttime conditions. Unfortunately when purchasing online it's difficult to really know how well a camera will perform so it's important to first know what "you" want from the camera then try to match that with a cameras description and specifications. Also it's always nice to get things as cheaply as possible but don't let price alone be your only consideration after all there is no point in investing even a small amount of your money if the evidence isn't there when you need it.

  There is no doubt the future of surveillance will be high definition and HD-SDI will certainly be high on the list of choices. High definition IP cameras have great images and many that exceed the 1080p or the current 2 megapixel limit of HD-SDI cameras but some knowledge of networking is generally required when setting up IP cameras. Some newer players in the HD market are HD-CVI and HD-TVI each with slightly different technologies for delivering high definition. They do have an advantage over HD-SDI in that they can be wired at longer distances and can also be used with Cat 5e or Cat 6 cable using video baluns. Whichever type camera you choose the increased resolution for identification and evidence will definitely be appreciated especially if you are serious about your security. Be sure to see our HD Security camera page for more information.