WHAT IS A HD CCTV System?
There are several types of analogue HD CCTV security cameras on the market, and they are all subtly different. HD systems are usually selected either for cost savings or system upgrades for cabling compatibility.
HD-SDI Cameras & DVR Recorder
HD-SDI was the first analogue HD security camera technology developed and transmitted HD over COAX cable. HD-SDI, although still widely available, has not progressed as a CCTV technology.
HD-CVI Cameras & DVR
HD-CVI technology manufacturer is the Chinese company Dahua. Dahua Technology is partially state-owned by Central Huijin Asset Management and China Securities Finance Co.Ltd.
HD-AHD Cameras & DVR
HD-AHD is a new recording technology developed by the Korean company Nextchip. Image quality is not as crisp as HD-TVI, and it is more limited in terms of compatibility. The main benefit is cost.
HD-TVI Cameras & DVR 
HD-TVI is our preferred CCTV security camera technology. The cable can be existing COAX, so it is ideal for system upgrades or CAT5e or CAT6 cable using video baluns.
HD-TVI produces crisp image quality of up to 8.0 Megapixel (4K) or 3840 x 2160 pixel resolution.
The other great thing about HD-TVI is that, unlike HD-CVI, which is only available from one Chinese company, HD-TVI developers were the American company Techpoint and the preferred technology of many CCTV manufacturers.
