That is not an ideal MP/sensor size combination and will struggle at night. And the 2.8mm fixed lens is the wrong camera to IDENTIFY someone at 25 feet.
It is simple LOL do not chase MP - do not buy a 4MP camera that is anything smaller than a 1/1.8" sensor. Do not buy a 2MP camera that is anything smaller than a 1/2.8" sensor. Do not buy a 4K (8MP) camera on anything smaller than a 1/1.2" sensor. Unfortunately, most 4k cams are on the same sensor as a 2MP and thus the 2MP will kick its butt all night long as the 4k will need 4 times the light than the 2MP... 4k will do very poor at night unless you have stadium quality lighting (well a lot of lighting LOL).
If you want to see things far away, you need optical zoom, digital zoom only works in the movies and TV...And the optical zoom is done real time - for a varifocal it is a set it and forget it. You cannot go to recorded video and optically zoom in later, at that point it is digital zoom, and the sensors on these cameras are so small which is why digital zoom doesn't work very well after the fact.
To identify someone with the 2.8mm lens that is popular, someone would have to be within 13 feet of the camera, but realistically within 10 feet after you dial it in to your settings. So yea, 25 feet will be almost impossible to IDENTIFY a stranger with a 2.8mm lens.
Here are my general distance recommendations, but switch out the Dahua 5442 series camera to the equivalent 2MP on the 1/2.8" sensor or equivalent Hikvision works as well.
- 5442 fixed lens 2.8mm - anything within 10 feet of camera OR as an overview camera
- 5442 ZE - varifocal - distances up to 40-50 feet (personally I wouldn't go past the 30 foot range but I like things closer)
- 5442 Z4E - anything up to 80-100 feet (personally I wouldn't go past 60 feet but I like things closer)
- 5241-Z12E - anything from 80 feet to almost 200 feet (personally I wouldn't go past 150 feet because I like things closer)
- 5241-Z12E - for a license plate cam that you would angle up the street to get plates up to about 175 feet away, or up to 220 with additional IR.
- 49225 PTZ - great PTZ and in conjunction with an NVR or Blue Iris and the cameras above that you can use as spotter cams to point the PTZ to the correct location to compliment the fixed cams.
You need to get the correct camera for the area trying to be covered. A 2.8mm to IDENTIFY someone 40 feet away is the wrong camera regardless of how good the camera is. A 2.8mm camera to IDENTIFY someone within 10 feet is a good choice OR it is an overview camera to see something happened but not be able to identify who.
Main keys are you can't locate the camera too high (not on the 2nd story or above 7 feet high unless it is for overview and not Identification purposes) or chase MP and you need to get the correct camera for the area trying to be covered. A 2.8mm to IDENTIFY someone 40 feet away is the wrong camera regardless of how good the camera is. A 2.8mm camera to IDENTIFY someone within 10 feet is a good choice OR it is an overview camera to see something happened but not be able to identify who. Also, do not chase marketing phrases like ColorVu and Full Color and the like - all cameras need light - simple physics...
