2MP is more than enough for LPR. Focal length, distance to plate, and shutter speed are more important. Heck I have an old analog camera at 720P that works just fine, and OpenALPR recommends 720P in some instances.
Heck I even created a thread showing OpenALPR can read plates with a D1 resolution....
We have folks come here all the time thinking that more MP is better, whether it be for general purposes or for LPR. Those of us that have been around long enough know that sensor size is more important than MP. Those that have been here awhile know that I share a representative sample of...
ipcamtalk.com
But your little 2.8mm fixed lens camera ain't gonna cut it unless the car is right on top of the camera moving at a slow speed.
The biggest thing we see is people always underestimate the actual distance. 50 feet turns out to be 75 feet and then the camera selected isn't the right one.
The Z12E is capable of reasonable distances of 150 feet, but people have been able to get it to 220 feet, especially with additional IR.
The Z4E is the next camera that people have tried, but most have found beyond 50 feet, it is difficult to make out the plates because the optical zoom of that camera is half of the Z12E optical zoom.
After that, it would be one of the varifocal turrets, but those will only reach about 30 feet, but do work well on a mailbox at the street. About half the price of the Z12E.
The Z12E and Z4E are the same price, so between the two, why not buy the one that provides the best opportunity to get a longer distance if needed.
During daytime it may act as an overview, but at night the shutter tends to need to be faster to capture the plate, and the faster the shutter, the darker the image.
Most of us run B/W to take advantage of the reflective properties of a plate which is why we can run a faster shutter to get the plates. Once you decide to keep it in color, the shutter speed slows way down and might not be fast enough to actually capture a plate.
At night, we have to run a very fast shutter speed (1/2,000) and in B/W with IR and the image will be black. All you will see are head/tail lights and the plate. Some people can get away with color if they have enough street lights, but most of us cannot. Here is a representative sample of plates I get at night of vehicles traveling about 45MPH at
175 feet from my Z12E camera (that is all that is needed for plates):
