TVI, CVI, SDI, AHD, IP – What’s it all about?
There are many different technologies involved when it comes to security cameras. The main ones you will have likely seen are:
These technologies primarily are how the camera and the recorder communicate the footage to be recorded.
This section gives you a brief overview of each technology – it’s not meant to be a comprehensive analysis of each as you’ll have likely died of boredom before getting to the end!
HD-TVI or TVI
This is our choice of technology. It was originally developed in the USA by an American company and then released as an open source platform for different manufacturers to use. TVI is an analog technology that supports Full HD 1080p resolution. It is incredibly compatible – you can use existing standard resolution D1/960H equipment. Not only that, but it is also compatible within the technology – you can mix 720p and 1080p cameras on the system (we only supply 1080p cameras however). It is not too fussy with regards to it’s wiring meaning you can use existing cabling. It’s happy to work with video baluns over CAT5e cable giving further options for wiring. Long cable runs aren’t an issue.
In short, when we first saw HD-TVI discussed, we were very excited here at Orange Security. It takes a lot to get us very excited!
Whilst we don’t feel there’s a requirement to push the resolution boundaries due to the practicalities of storing all that information, HD-TVI is capable for higher resolutions so there’s an element of future proofing build in.
HD-CVI or CVI
This is a Chinese technology created by a company called Dahua. There are so many compatibility issues, even within the technology itself it was never going to be the technology to use. Not only that, but more recent technology isn’t compatible with earlier CVI technology!
HD-SDI or SDI
This really was the first analog high definition that was released onto the market. It didn’t do a bad job, however as a technology it did have it’s limitations. When we first saw this technology, it was obvious it wasn’t going to be a long-termer! First and foremost, it was not backwards with any existing components of cabling. You had to use very specific cabling which often meant that if you wanted to upgrade to HD-SDI you’d be renewing the cabling used in your system and often the short cable run limits made installation difficult. You will now see cheap cameras advertised on eBay that turn out to be SDI – avoid as you’ll be left high and dry in the future!
This is also an analog, high definition, technology also originating from China. It is cheap. The image quality is not as good as our yard-stick, HD-TVI.
The real benefit of IP cameras is that you can use existing networks to send the video signal from your camera to your recorder. You also can acquire high resolution IP cameras. This is great in theory however in reality once you start using multiple IP cameras in anger you will start to overload your network and router to the detriment of the other usage of the network. This issue is amplified even more so when you start to use cameras that produce many mega pixels.
Often you will find the setup and configuration of IP cameras to be a challenge at best! When it works, it’s simple – however when it doesn’t then it can be a nightmare! One of many causes is manufacturers claiming their products are ONVIF compliant but turn out not to be. How can this be, you may ask? Well – ONVIF is a self-signed certificate standard and some less reputable manufacturers will advertise their products as meeting the ONVIF standard but in reality they don’t (or only partially do).
Have you ever had an internet issue and tried to speak with your cable provider to solve the issue? Solving technical problems with IP cameras can be just as frustrating!
The other way IP cameras can be used is by running an ethernet cable from the recorder straight to the camera however you then end up with the complicated IP configuration issues whilst still having to run a dedicated cable from the recorder to the camera.
Whilst we don’t think that IP cameras are what should be primarily used for a security camera system, we do recognize that in some situations there is no other option for a camera as part of an overall system. The recorders we stock have a bonus IP channel that allows you to connect a remote camera to your network where it may be otherwise difficult to run a cable to.
Top Tip: You will often see companies selling equipment at too-good-to-be-true prices and not telling you which technology is being used. Avoid these guys as they’ll likely be selling one of the inferior technologies that either are or will soon be obsolete!