If it's not HD, the picture is very blurred. What's the use of monitoring the camera?

Therefore, it is best to use a high-definition camera, but there is no need to pursue pure high-definition, just enough.

For example, I used the Harmony surveillance camera, 1080P. If you say HD, it is not HD, but the surveillance screen is completely enough, and there is night vision function. It's still very useful.