If your cameras are not showing a far enough video image at nighttime, there are a few ways to extend the night vision distance.
The first thing is to make sure that the cameras are receiving enough amperage. Under-powered cameras will show a shorter night vision distance than cameras that are powered correctly. If you see any white interference lines either during the day or at night, this is an indication that the cameras are not receiving enough voltage and amperage. You can also test whether the cameras are getting adequate power by plugging a camera directly into the power adapter that it came with, instead of running any wire in between the power adapter and the camera. If there is a great improvement in image quality when the camera is plugged directly into its power source, you may need to upgrade your cable thickness or power your cameras directly in order to achieve optimal night vision.
If your cameras are powered correctly and the night vision is still shorter than you prefer, we recommend installing an IR extender next to any cameras that would benefit from longer night vision. A variety of IR night vision extenders can be found for sale on Amazon.com
We have tested the following product, and we most highly recommend this product based on effectiveness and cost efficiency:
The following image was taken from our test results of this IR extender: