I picked up a bunch of 4k POE "simicam" cameras from AliExpress for 25 euros each. These serve up RTSP streams to frigate. I made some minor frigate config changes - I set it to keep 7 days of full recordings (just because i am paranoid), so this uses approx 1Tb of storage (5 cameras currently, more to go online soon). Frigate is running on an old laptop with a Coral AI USB and 2Tb NVME for storage. I enabled detection of cars and animals as well as the default of just humans. It works pretty well, but has some annoying quirks, e.g. if a dog runs past where a car is parked it will trigger an alert for both a dog and a car. It also detects weird conglomerate shapes as human sometimes, e.g. a bucket left at the end of some rolled up bird netting with some pieces of timber sticking out underneath can be vaguely human shaped when viewed from a height. I run the free open source version, and I'm sure I could get better results if I played with the configuration more.
Its hit and miss to be honest. They do have a day/night mode. One camera is indoors in a shed - it picks up moths (as birds) and even a bat a couple of times. One camera that is outdoors regularly detects the fox that visits us almost every night. However another camera pointed at his next destination never picks the fox up at all. The main difference between the two camera environments appears to be third party lighting - there are street lights in the direction of the one that does not detect the fox, and also the glow of a robot mowers charger light. One or both seems to be putting off the cameras ambient light sensor and prevents night mode from kicking in. The simicams do have some configuration for night mode also, none of which I have tried out yet. Options like infrared lamp vs white lamp vs dual, and day-night mode of "photoresistor" vs "scene brightness" and also some "color to black luma" and "black to color brightness" settings. I should really play with those some more, but they've been left as defaults so far.
I have a cheap 25 euro PoE cameras from aliexpress that gives decent video quality. The night vision though is lacking in comparison to one Brillcam that I have. The cameras are connected to a cheap 20 euro PoE switches that advertise being able to put out 60W of power.
For NVR I am using raspberry pi5 4gb model with a dedicated 2.5 inch hard drive that is only used for recording where micro SD card is used for everything else. All the pieces fit in a dedicated case:
