Many users of LTS products may already be familiar with the term, "resolution" as it is commonly used across tvs, phones, computers, and more. "Resolution" is merely the overall sharpness of the picture. But how is this measured? More importantly, what is creating the image you see on your CCTV camera?
TVL
Analog and TVI cameras are not based on pixels. Instead, they are based on TV Lines, or TVL. TV lines are a measurement of the number of vertical/horizontal lines a camera records.The quality of analog video is determined by how many TV lines there are and the image sensors on the cameras.
What is XXXTVL?
The general rule of thumb to determine the quality of your analog video is by looking at how many TV lines there are. The more there are, the higher the resolution. 800TVL would be higher quality than a camera that outputs 400TVL.
What do the numbers mean?
400TVL means there are 200 dark and 200 light alternating lines
Pixels
IP surveillance cameras today do not use TVL, they utilize pixels instead to generate video feeds. Resolutions are measured based on how many pixels there are. For instance, 1 megapixels is equal to one million pixels. If we go off by resolutions, 1920 x 1080, is the equivalent of 2073600 pixels. Pixels are so tightly packed that together, each colored section ultimately comes together to form an image.
How does the number of pixels affect my image quality?
The resolution determines how many pixels there are. The image quality increases as the number of pixels increase. As the number of pixels goes down, the quality goes down. This is because when you have less pixels, the camera still need to creates the same image. This forces pixels to spread out to create the same image. Kindly find below, the differences between 4 million pixels and 84,480 pixels.
4MP (2592x1520) 352x240