FAQ about AHD video technology (click icon bellow to show all)
AHD CCTV is an analog high definition closed-circuit television video surveillance standard that uses existing coax cable to transmit 720p and 1080p video resolutions HD video from security cameras to DVRs.
AHD is able to transmit up to 1080p video resolution (1920 x 1080) in an uncompressed format over the same standard coaxial cable that is used for standard CCTV cameras.
This uncompressed video format is able to transmit over longer distances than either HD-SDI or Network IP cameras and without the latency and bandwidth issues that are so common with IP Cameras.
Additionally, AHD is able to transmit video, audio and control (OSD or PTZ) over a single coaxial cable instead of requiring separate cables for each transmission.
What is really separating this technology from the rest of the options for HD video transmission is the cost effectiveness of AHD. In most cases AHD is around the same price as the older analog CCTV technology and is far less expensive than HD-SDI or IP Network transmission.
15 quick advantages of HD Analogue Technologies over HD IP Technologies ( IP CAM)
- AHD has visually better live picture quality als IP HD solution because of simple fact that picture is non compressed
- Because image from camera comes to DVR uncompressed, (without any degradation from compression process) and in real time all video analytics that is performed in DVR gives better results
- Because there is no need for compression in camera there is no lag (that exist in IP CCTV) - live picture is real time as can be. ( Why lags in IP CCTV ? IP CCTV does compress picture inside camera, send compressed video over LAN and when picture comes to NVR must be uncompressed first - and all this take time.. so this is reason for possible lags )
- The technology is very similar to analogue CCTV. All cameras are directly connected to the associated DVR
- It utilises the same 75 Ohm coaxial cable as the analogue CCTV technology is using (it will work with copper clad aluminum coax) , but instead of transmitting only video it transmits simultaneously 3 signals together - video, audio and serial data
- Transmitted signals are immune to external electromagnetic interference
- Maximum distance between camera and DVR is 500 m
- It achieves instant signal transmission with no compression, no latency and no delay
- Delivers HD quality video image. Supports 720p (1280 x 720 pixels) and 1080p (1920 x 1080) pixels, that’s full HD
- Complies with open standard which guarantees compatibility among the devices from different manufacturers with the same technology
- Low ownership and maintenance cost. Almost the same cost as for the good old-fashioned.
- AHD deliver Progressive-Scan HD analogue video ( full frame, and not half frame like in old analog CCTV).
- AHD follow the same wiring regulation with 960H, which means customers can upgraded their 960H to HD CCTV easily by just replace the Camera&DVR.
- Compared with HD-SDI, AHD have a longer transmit distance without any signal loss.
- Compared with IP CCTV, AHD don’t have problems such as delay, signal loss.
Maybe is at this point good to clarify one fact: It’s a popular misconception that only video from IP CCTV cameras can be viewed remote on mobile devices - If you use AHD you can still connect to video picture of any camera from anywhere in the world via IP protocol with your computer or mobile device, since AHD DVR is normaly connected to IP network ( LAN or WAN ), so remote access is same als in IP CCTV cameras.
What is AHD HD?
AHD stands for Analog High Definition Composite Video Interface. This is a brand new technology in the security camera industry that provides a different method of transmitting video signals over coaxial cables. Until this new technology surfaced, analog CCTV video was limited to 960h video resolution, so the maximum analog resolution up to this point was 960 x 480 pixels. This has been the accepted limit to analog video transmission for many years. In order to achieve greater transmission would mean switching to digital video using either HD-SDI (High Definition Serial Digital Interface) or Network IP video formats.
What type of cable do AHD cameras use?
AHD CCTV cameras are connected to DVRs using the same type of coaxial cable as traditional analog CCTV cameras , typically RG59 or RG6 coax cable. One of the advantages of AHD over HD-SDI cameras (another HD over coax security camera standard), is that RG59 coax cable can be run long distances without video loss. AHD cameras can also use UTP cable with video baluns to run cable up to 320 Meters / 960 feet with CAT5 cable.
Will AHD replace analog CCTV cameras?
Some people in the surveillance industry thought that analog CCTV would have been phased out years ago. Around 2007, megapixel resolution IP cameras were gaining popularity. However, most found that IP cameras tend to be more difficult to setup and the pricing never came down enough for many to justify the higher resolution. First version of HD-SDI came to the surveillance industry about 2010 (it has been used to make movies and HDTV for years). Although quality HD-SDI cameras, the acceptance of them has been limited. Some say it is because you can not run coax cable very long distances for HD-SDI and there is no support for video baluns (to use with UTP cable). The image quality of 1080p HD-SDI is outstanding though. AHD seems to address the main issues that held back the other HD security camera types from taking over the analog CCTV market. Installers can use the same coax cable as traditional analog CCTV cameras and they work at the same max distance. Video baluns for AHD cameras are available for those that prefer to use UTP cable such as CAT5. Pricing on AHD cameras is only slightly more than analog. Last, there are high quality hybrid DVRs available that let users use both AHD and analog CCTV cameras. This will allow security system owners to use their existing CCTV cameras and upgrade over time to HD, while keeping their DVR in place.
Suitable for following types of installations
1. In general all new small to medium scale CCTV installations in a future, should be done with the best one of the 3 HD analogue solutions which is the AHD technology
2. Good for small scale CCTV installations with up to 16 x cameras and 1 DVR
3. Good for domestic and also for small to medium commercial and industrial buildings
4. The most economical choice in cases where the new installation is going to utilise the existing network of coax/fig 8 cables, inherited from the previous CCTV installation
5. Preferred option for a low budget and low maintenance CCTV installations.¦
AHD stands for analog high definition, AHD is based on AHD standard which developed by Korean chip-set manufacturer - NextChip.
Similar to traditional CCTV equipment, AHD camera can deliver uncompressed HD video over Cat75-3 coaxial cable, AHD is able to deliver uncompressed 720p / 1080p high definition video over Cat 75-3 coaxial cable, and transmission distance up to 500 meters. This technology breakthrough the current HD video transmission limitation (<= 100 meters), it can achieve low-cost, long range, no video latency, high efficient megapixel resolution video transmission.
The HD including several different resolution formats, they are 1080i, 720P, 1080P. 1080i60 stands 1920x1080, adopts interlaced scan, 30 frames per second; 720P60 means resolution reaches 1280x720, adopting progressive scan, 60 frames per second; 1080P60 means resolution reaches up to 1920x1080, adopting progressive scan, 60 frames per second.
AHD different from 960H that utilizes CCD image sensor, AHD adopt the megapixel resolution progressive scan CMOS image sensor. The megapixel CMOS image sensor is able to capture images with high definition resolution. The widely used CMOS image sensors are from Aptina, Sony, Omnivision, Pixelplus.
AHD is open standard, which allows hundreds of manufacturers develop analog security cameras based on these technologies. Additionally, compared with other technologies, the cost for AHD is extreme low, end-users can enjoy the analog high definition video surveillance with same price as traditional analog camera.
AHD has three versions: AHD 0.8, AHD 1.0 and AHD 2.0. AHD 1.0 can support 720p high definition (HD) video capturing and recording. AHD 2.0 can support 1080p full high definition (FHD) resolution.
AHDL: AHD 0.8, works with 960H AHD cameras and traditional analog cameras
AHDM: AHD 1.0, works with 960P/720P/960H AHD cameras
AHDH: AHD 2.0, works with 1080P/960P/720P/960H AHD cameras
AHD 3.0 with megapixel resolution is coming ...
Depending on your AHD cameras: AHD cameras have total three formats; AHD 0.8, AHD 1.0, AHD 2.0. If you choose AHD camera that supports AHD 0.8 format, then camera will deliver 960H resolution, so it works with your traditional 960H DVR. This is the reason why Nextchip claims AHD is back-compatible with conventional analog video surveillance system.
When comparing AHD (analog high definition) to Network IP cameras:
IP cameras cannot transmit video over coaxial cable natively so the infrastructure must be built with ethernet cable or fiber. AHD (analog high definition) 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. AHD (analog high definition) can transmit video over 1500 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. AHD (analog high definition) cameras do not consume any network bandwidth nor do they have latency or collision issues. This means that AHD (analog high definition) will not interfere with the operation of your network and is much simpler to install and configure.
AHD (analog high definition) technology is much less expensive than IP Network cameras and recorders.
There are some benefits to IP cameras over AHD (analog high definition) cameras that should be considered as well:
IP cameras are capable of higher resolution than 1080p and the available resolutions will continue to grow in the future.
IP cameras are capable of POE power so you can transmit both power and video on a single ethernet cable if using a POE camera and a POE switch.
An IP camera is a network device itself so it can function without the need for a network video recorder.
If there is an existing network infrastructure and available network bandwidth is not an issue, it can be easier to add additional IP cameras to an existing network.
When comparing AHD (analog high definition) to Analog CCTV cameras:
CCTV cameras are limited to 960h resolution which is 960 x 480 pixels. AHD (analog high definition) cameras can transmit up to 1080p resolution (2 Megapixel) which is 1920 x 1080 pixels. AHD (analog high definition) is capable of up to 450% great resolution and detail than standard CCTV cameras and DVRs.
CCTV can only transmit video over the single coaxial cable. Audio and control must be run over separate cables. AHD (analog high definition) can transmit video, audio and control over a single cable saving money and time.
The price point of analog CCTV and AHD (analog high definition) is about the same. You get more resolution for the money with AHD (analog high definition).
When comparing AHD (analog high definition) to HD-SDI the benefits are:
Longer video transmission distances. HD-SDI is limited to 333 feet for video transmission. AHD (analog high definition) can be transmitted up to 1500ft.
HD-SDI can only transmit video. AHD (analog high definition) can transmit video, audio and control requiring less cable infrastructure.
HD-SDI can only transmit over high quality copper core coaxial cable. AHD (analog high definition) can transmit over any cable used for CCTV cameras. It will work with copper clad aluminum, Ethernet cable with video baluns and even prefabricated plug and play cables.
AHD (analog high definition) is less expensive than HD-SDI.
Weaknesses of AHD :
- Integration with complex integrated access control/intrusion systems is very limited because of the lack of support from the major developers and manufacturers
- Maximum video resolution can only go to Full HD for now (1920 x 1080 pixels)
- The video image under low light conditions is still not as good as conventional analogue CCD cameras because the image sensor technology is CMOS rather than CCD.