I bet you've come across this question at some point. "What are the differences between analog cameras, HD-TVI, HD-CVI and AHD?"

So it's time to find the best and most complete answer to this question.

I will describe what the three technologies have in common and later in the article I will explain the individual differences of each one of them.

When you are looking for security cameras on the market you always find some advertising about hybrid DVRs that support different types of cameras, some of these DVRs support cameras with traditional analog technology, and also HD-TVI, HD-CVI, AHD and sometimes even IP cameras.

Any of the 3 technologies can provide sufficient resolution for most projects. There is a race between manufacturers to be in the lead and deliver cameras that stand out primarily in high resolution, but in practice most cameras installed have either HD resolution or FullHD.

Different manufacturers have HD-TVI, HD-CVI and AHD technologies with FullHD resolutions also known as 108op or 2Mega Pixel

HD-TVI, HD-CVI and AHD are analog, it is important to emphasize this fact because the security camera dealers are always advertising that their equipment support those 3 technologies and also support analog cameras.

What they really should say is that their equipment support old traditional low resolution analog cameras and also support the new high resolution analog cameras with HD-TVI. HD-CVI and AHD technologies.

The way the advertising is shown may lead one to believe that HD-TVI, HD-CVI and AHD are not analog technologies, see an AD example below"

"The DVR supports HD-TVI, HD-CVI, AHD , IP and analog cameras"

In fact, what the vendor intends to say is that the DVR can accept the 3 high-resolution analog camera technologies (HD-TVI, HD-CVI and AHD), as well as accept IP technology and traditional low-resolution analog technology, which are actually the analog cameras with CVBS technology.

Imagine a situation in which you need to replace old security cameras for your client as he intends to get rid of traditional models and migrate to the high resolution ones.

Your client already has several traditional analog cameras installed on site and therefore there is also an entire infrastructure already installed with traditional coaxial cables such as RG59, RG6 or RG11. (For more information on coaxial cables read the article: Coaxial Cables for CCTV).

The cost of replacing low-resolution analog cameras for high-resolution analog cameras could be very high if there was a need to also replace the infrastructure and all coaxial cables

This is where HD-TVI, HD-CVI and AHD cameras become very interesting because they can use the same types of coaxial cables as traditional analog cameras, which means they can help you to save money.

IP cameras are still more expensive compared to HD-TVI, HD-CVI and AHD cameras. But there is a lot of difference between these technologies. To learn more about IP cameras read: The advantages of IP cameras

In projects that do not require embedded intelligence or more advanced features, analog technology is still a good option for the customer.

Here's an example of a price comparison between a camera with HD-TVI technology and another with IP technology. Both models are bullet type, with 1080p (2MP) resolution, 2.8mm lens and infrared.

Price for Hikvision Bullet 2MP (1080p) IP camera

Price for Hikvision Bullet 2MP (1080p) HD-TVI  camera

That's just a fast comparison, there are other things to take in consideration, but you can have an overall idea that IP is a little bit more expensive.

Now is the time to know more about the individual characteristics of each of the technologies. The comparison is as neutral as possible without supporting any of the technologies.

High Definition Transport Video Interface

Developed by a Japanese company called Techpoint, HD-TVI technology started in the market initially with 720p (HD) and 1080p (Full HD) cameras and recorders.

The Chinese company Hikvision is the largest camera manufacturer using this HD-TVI technology with Techpoint chips. Hikvision distributes its products around the world in different ways, one of them is using the brand itself and the other is through white label products, where the logo does not appear in the product and third companies can put their own brand.

The technology was created in 2014 with the goal to transmit analog signals using coaxial cables at distances up to 500m.

In 2016 Hikvision announced that with the improvements of the technology in the version Turbo HDTVI 3.0 it would be possible to transmit 720p resolution images at distances up to 1,200m and 1080p resolution images up to 800m.

With new versions of the technology, 4MP, 5MP cameras were manufactured and later came the cameras with 4K resolutions (8MP).

Another important feature to be mentioned is that with HD-TVI version 3.0 it is possible to send video and power through the same coaxial cable, technology known as POC (Power over Coax).

(To learn more read the article: What is Power Over Coax for CCTV )

High Definition Composite Video Interface

Launched in 2012 by Chinese company Dahua, HD-CVI technology has hit the market to revolutionize the use of high resolution analog cameras

The first cameras were models with 720p and 1080p resolution. By 2014 the company was already launching the HD-CVI 2.0 version of the technology that continued to advance each year with the launch of new products with high resolutions and the possibility of using cables with greater distances.

Dahua manufactures the cameras themselves and also allows the use of the technology by other companies around the world.

In the HD-CVI version 3.0 the company announced resolutions of up to 4K (8MP) and the POC (Power Over Coax) technology that allows to send power, data and video through the conventional coaxial cable.

Analog High Definition

Developed by Korean company Nextchip, AHD technology has brought the 720p and 108op high resolution analog cameras to market.

The company supplies its chip with AHD technology to major manufacturers such as Hanwha Techwin and other companies worldwide.

At first AHD 1.0 technology allowed the use of 720p resolution cameras. The new AHD 2.0 version introduced 1080p resolution using traditional coaxial cable (RG59) at distances of up to 500m.

The developer of this technology claims that AHD has the advantage of greater compatibility with systems, but in practice it does not seem to have real advantages.

An AHD camera should connect directly to a traditional monitor with BNC input and display images. However the image displayed is black and white and depending on the AHD version some compatibility problems may occur.

Compatibility with traditional DVRs with 960H resolution is also limited as it only works on cameras with older versions.

It is important to be careful when buying an AHD camera because in the market it is possible to find different nomenclatures like AHD-L, AHD-M and AHD-H that represent Low, Medium and High resolutions respectively. An AHD-L camera has less than HD resolution, the AHD-M has 720p resolution and finally the AHD-H has 1080p resolution.

See the images below comparing the 3 technologies. These tests were conducted by the American company Clinton Electronics.

Image of a moving vehicle during the day

Images of a casino table, note the color differences

Images of parked cars during the day

Images in environment with low illumination, note the noise.

Side by side comparison

According to Clinton Electronics tests were performed with the cameras using factory default settings, so there may be margins for quality adjustments. Video compression did not affect the tests due to the use of an external recorder device for all cameras.

You can visit the manufacturer site to look for distributor in your region

For HD-TVI cameras

http://www.hikvision.com

For HD-CVI cameras

http://www.dahuasecurity.com/

For AHD cameras

http://hanwhasecurity.com

One important thing to keep in mind is that most cameras already work with more than one technology and are considered hybrids, you can connect them to a HD-TVI, HD-CVI or AHD DVR. So consider buying these types of hybrid cameras and if you want to have more flexibility.

The market has adopted the use of high-resolution analog cameras as an alternative to traditional analogue (CVBS) technology and customers can count on better products and image quality.

Competition between HD-TVI, HD-CVI and AHD technologies helps reduce product costs and improve quality each year. It is important, however, to analyze which products best meet the needs of your customers.

Stay alert not only to the technology discussed here but also to other factors that can affect quality such as building material, quality of infrared LEDs, brand, training and technical support.