Some excerpts from my standard welcome blurb -
Don't chase megapixels unless you have a really BIG budget. Chase sensor size and bigger is better. To confuse you more sensor sizes are listed in fractions so do the basic math to be sure, 1/2.8 is bigger than 1/2.7 or 1/3. General rule of thumb is that a 4MP camera will easily outperform an 8MP camera when they both have the same sensor size. Reason being that there are twice as many pixels in the 8MP versus the 4MP. This results in only half the available light getting to each pixel in an 8MP that a pixel in the 4MP "sees".
The smaller the lux number the better the low light performance. 0.002 is better than 0.02
The smaller the "F" of the lens the better the low light performance. F1.4 is better than F1.8
The larger the sensor the better the low light performance. 1/1.8" is better (bigger) than 1/2.7"
The higher the megapixels for the same size sensor the worse the low light performance. A 4MP camera with a 1/1.8" sensor will perform better than a 8MP camera with that same 1/1.8" sensor.
Don't believe all the marketing hype no matter who makes the camera. Don't believe those nice night time captures they all use. Look for videos, with motion, to determine low light performance. Any camera can be made to "see" color at night if the exposure time is long enough, as in half a second or longer. Rule of thumb, the shutter speed needs to be at 1/60 or higher to get night video without blurring.
Read the reviews here, most include both still shots and video.
Avoid Reolink, Foscam, SV3C, Nest, and all the other consumer grade cameras. They all struggle mightily at night and never get anything useful on video. Here's a link to a whole thread debunking Reolink in particular.
Compiled by mat200 -
Executive Summary: DO NOT be a sheep. Ask what a reviewer can be missing, ask if a reviewer is using hype words to sell the cheapest product. Test your cameras and kits right away. Just do a bench test. Test real world conditions. Test moving suspects. Test at night, test at day. Use a test rig...
ipcamtalk.com
Avoid WiFi cameras, even doorbell cameras. WiFi is not designed for the constant, 24/7, load of video that a surveillance camera produces. At best, with two cameras on WiFi, they will still experience dropouts multiple times daily. Murphy's Law says that will happen at the worst possible moment.