When selecting a reversing camera for your vehicle, it is crucial to understand the different types of video signals they use. The two main types of analog video signals are CVBS and AHD. While both produce good picture quality, there are significant differences between them that can impact your choice.
CVBS stands for Composite Video Baseband Signal. It is the more traditional of the two, having been used for many years in various video applications. CVBS cameras produce a composite video signal, which is a single-channel analog signal carrying standard-definition video. Despite its age, CVBS continues to provide a reliable and good-quality picture for many applications, including reversing cameras.
AHD stands for Analog High Definition. As the name suggests, AHD cameras provide a higher-definition video signal compared to CVBS. AHD is a newer technology that improves the clarity and detail of the video image, making it a popular choice for modern reversing cameras. Both CVBS and AHD are analog video signals, which means they produce no lag compared to some complete digital video signals, making them ideal for real-time applications like reversing cameras.
Both CVBS and AHD signals can use either NTSC or PAL formats, which are standards for how video is transmitted and displayed.
NTSC stands for National Television Standards Committee. This format was developed for the television system used in the United States, Japan, and many other countries. NTSC video is made up of 525 interlaced lines and is displayed at a rate of 29.97 frames per second (often rounded to 30Hz).
PAL stands for Phase Alternate Line. This format is used in many European countries and other parts of the world. A PAL video is made up of 625 interlaced lines and is displayed at a rate of 25 frames per second (25Hz).
In discussions about CVBS cameras, you will often hear references to NTSC or PAL. For AHD cameras, you might hear the terms 25Hz (PAL) or 30Hz (NTSC). It is important to note that Hz in this context refers to the frame rate and is another way of indicating whether the camera uses the NTSC or PAL format.
Refer to our chart below for a clearer understanding:
Why is understanding these formats important? Because various monitors, head units, and factory head units may only accept one type of format, or they might be compatible with all types. If you plug an AHD camera into a CVBS-only monitor, you will see no picture because the monitor cannot process the high-definition signal.
Each monitor and camera on our website will now have specifications listed in the “Additional Information” tab, advising what format it is and if it is a monitor, what format it accepts.
We also have a module available that will convert the AHD signal to CVBS so that your CVBS-only monitor will accept the AHD camera. Remember that the video quality will slightly drop when converting back to CVBS format.
When choosing between AHD and CVBS cameras, it is essential to consider the type of monitor or head unit you have and whether it supports NTSC or PAL formats. Understanding these differences will ensure that you select the right camera for your system, providing you with the best possible picture quality and compatibility.
If you are still unsure of what format you require, feel free to reach out to us at Polaris. One of our friendly staff members will help you assess your needs and get you on the right path.
