HD-CVI stands for High Definition Composite Video Interface. It’s a technology used to transmit high-definition analog video over coaxial cable. HD-CVI cameras are a great alternative to traditional analog CCTV and megapixel IP surveillance cameras because of their superior video quality and ability to use RG59 coax cable.
HD-CVI cameras are used by professional and DIY installers because they are so affordable and simple to install. For recording, HD-CVI security cameras must be used with a CVI-compatible DVR.
The benefits of HD-CVI technology
By using the HD-CVI technology it’s possible to transmit HD (High-Definition) video over long distances using the traditional coaxial cables such as RG59 and RG6 which reduces the cost of infrastructure, especially when an old analog CCTV system is being upgraded with the addition of high-resolution cameras.
It’s interesting to have a technology that still keeps the principle of analog video transmission but with the benefits of better image quality.
Before the high-resolution analog cameras, the only solution to upgrade and improve an old CCTV system was to offer the IP technology which comes with the need for infrastructure changes such as replacing the coaxial cable for the UTP cables or using transceivers with the technology Ethernet over coax.
The HDCVI 3.0
Since its creation in 2012, the HD-CVI technology has evolved from the 720p 1080p and 4K resolution. It is now in the 3.0 version which allows the transmission of HD video, audio, data, and even power over a coaxial cable.
Another important improvement in the HDCVI 3.0 is the implementation of the Starlight technology which allows obtaining crisp and clear images even in low light conditions. A camera that uses such technology only needs 0.008 lux of light to generate useful images.
This version also brings the WDR (Wide Dynamic Range) technology with 120dB to 140dB (higher is better) to improve images in an area with light contrast. The ASC (Automatic Signal Compensation) is also part of the HD-CVI technology and allows for a low distortion signal over long distances. You can install an HD-CVI camera up to 500-700m (1600 ft) away from the HD-CVI video recorder.
HD-CVI is a little different from other analog and HD-type cameras. Unlike other variations, you’ll find that in most cases, you’ll need to be using solid copper RG59 siamese cable. Why?
Well, it’s because HD-CVI cameras are capable of transmitting video up to 1600 feet. Gone are the days of being limited to runs up to 300 feet with standard analog and other HD cameras.
All of this being said, you still need to pay close attention to your power runs. While video can be transmitted over coax up to 1600 feet, your power cable is still going to be limited to 300 feet.
You can augment this with higher voltage power supplies and converters but make sure you know what you’re doing before you accidentally end up frying your cameras.
The standard copper-clad RG59 cable will still work with HD-CVI camera systems. If you go this route, you may experience video degradation.
Up to about 250 feet, you shouldn’t really notice any loss in image quality, but after that, you’ll notice a faded contrast, lines starting to form, and a shadowing effect. You’ll never fully lose your video feed, but these negative effects will gradually get worse.
Using Cat5e cable with video baluns is another option but it’s limited. At only 150 feet, you begin to see the same loss in contrast. At 300 feet, lines, and shadowing start to appear. Like the copper-clad RG59, you’ll never fully lose your image, but it will continue to go downhill. If you use Cat6 cables, it will provide a better image quality.
Years ago it was necessary to run extra cables to control a PTZ (pan, tilt, zoom) camera thus increasing the cost of infrastructure. With modern technology comes the solution such as the PTZ command control over coaxial cables.
This technology was invented many years ago by Pelco with the name coaxitron and later other manufacturers such as Samsung and Hikvision created their own protocol. And Dahua, the patent holder of HD-CVI, did the same with the HDCVI technology.
The DVRs (Digital Video Recorders) that support the HD-CVI 3.0 can be considered as hybrid devices since they support the use of AHD, IP, HD-CVI, and HD-TVI cameras which is a huge advantage for the compatibility and upgrading the system.
The HD-CVI 3.0 technology supports intelligent features such as face recognition, people counting, smart tracking, smart scene adaptation, and heat mapping.
The most common IP cameras’ intelligent video features such as scene change, virtual tripwire, and missing/abandoned objects are also supported by the HD-CVI 3.0 which allows the use of advanced analytics at a reduced price.
HD-CVI cameras vs IP cameras
- IP cameras cannot transmit video over coaxial cable natively so the infrastructure must be built with Ethernet cable or fiber. HD-CVI can transmit over coaxial cable or Ethernet cable using video baluns allowing the use of existing infrastructure saving money and time.
- IP cameras cannot transmit video for distances over 333 feet without using relay devices on Ethernet cable. HD-CVI can transmit video over 1600 feet without using relay devices over coax or Ethernet cable.
- IP cameras require bandwidth considerations and are subject to latency and collisions as well as IP conflicts. HD-CVI cameras do not consume any network bandwidth nor do they have latency or collision issues. This means that HD-CVI will not interfere with the operation of your network and is much simpler to install and configure.
- HD-CVI technology is much less expensive than IP network cameras and recorders.
Where to buy HDCVI cameras and recorders
The HDCVI technology came to give extra life to the analog systems and allow to have better high-definition cameras with lower prices. HDCVI equipment is available on distributors, resellers, and even on the Amazon Store.