I started off with one of those 4K systems from Costco. It did well enough if there was no or little motion and a lot of light. Basically, if anything happened at night, you'd be able to see that something happened, but not well enough to identify anyone. That's also why most people in the know don't/won't recommend Reolink for night or high motion areas. Here is an example from Reolink's marketing videos - do you see a person in this picture? The person is in between the two columns.
Attached FileI ended up dumping that and setting up
Blue Iris. It's a software that works with pretty much any camera on a windows machine. You can tailor it and the cameras to your specific needs. There's a lot of things that go into the cameras besides just megapixls. The general 2.8mm lens is going to give you a wider field but the 6mm lens will give you a clearer picture on the same camera. A larger lens will capture more light and be better at night.
I'm using mostly cameras that have color at night. A newer technology is a blend of color and IR. It mixes the detail of IR with the clarity of color. Here's a picture of my driveway last night at 3 in the morning. You can see some of the red in the left tail light of my Yukon but on the right side, it's just black and white from the IR. BTW, it is pitch black out with only a fairly dim street light.
Attached FileHere's a picture from my phone with what it actually looks like.
Attached FileI'm also running dedicated license plate readers for any traffic that passes along the main road in front of the house. Obviously, the vehicle is recorded as it drives by but the cameras have dedicated AI that will record the plate. It works pretty well, though sometimes it'll be off. For instance, it appears that the one plate listed says "CANNON" but it recorded it as C44VON.
Attached FileMy house is on an acre in the suburbs and every inch is covered. I think I have 24 cameras in total divided up into different zones. A few focus on the front porch and front door. If anyone swipes an amazon package, I'll have about 6 different angles of them. Back and side yards are covered. And, I have a couple that are mounted high up for overview. I can see when the school bus is coming for the kids when it's two blocks away.
Blue Iris does take some tweaking to get right, but once it's there, you're set. I'm happy with it and I'll never use anything else. I'm not sure what I have in my setup...probably a few thousand with the 10GbE POE switch and the dual function cameras and license plate readers. You can start out pretty cheap though with a used ebay windows machine and a couple quality Hikvision or Dahua cameras. (There are other cameras that are decent but those are the most bang for the buck quality). Overall, you could put together a decent 4 or 6 camera system for only a few hundred bucks and it perform better than any packaged NVR. Again though, it'll take some tinkering and trial and error.