Two IPC-HDW2231R-ZS for LPR?

The snapshot you posted is only 913 x 511 pixels, which is less than 6% of the resolution the camera is capable of. The native resolution of this camera is 3840 x 2160 and you need all of it to get that approximate 34 foot max range for plate capture. To get the most out of the camera, you should cut its frame rate down to 10 or 15 FPS, max out the bit rate, and use an iframe interval that is 2-4 times the frame rate (e.g. frame rate of 15, iframe interval between 30 and 60). Additionally it should help a lot to enable the "region of interest" function at max quality in the specific areas where plates will be read from, which would be roughly where I have drawn these 3 rectangles. When used in a small area like this, Region of Interest can greatly enhance fine detail from what the camera will capture without it.

upload_2019-6-19_7-44-37.png

If your license plate recognition software supports it, you would also want to limit the region it analyzes to the same area in order to make it run faster.
 
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As @bigredfish says, the further the plate is down the road, the better the angle will be for reading the plate. But it will also make the plate smaller. This is where the longest lens option (6mm) would have been beneficial, since it would have nearly doubled the effective range of the camera.

I still think you will be okay with the 4mm lens once you get everything set up properly, and that includes mounting the camera closer to the road as pictured in your original plan because that gets you significantly better angles.
 
I may try the Region of Interest thing @bp2008 thx.
 
bp2008 said:
The snapshot you posted is only 913 x 511 pixels, which is less than 6% of the resolution the camera is capable of. The native resolution of this camera is 3840 x 2160 and you need all of it to get that approximate 34-foot max range for plate capture.
Click to expand...

I understand what you are saying. I am using this for LPR with ALPR. I was showing you a similar resolution to what works with ALPR. The recommended highest resolution is 1080p. In this case, 1920*1080. That is where the issue comes in. At the high resolution, the camera is capable of, 3840 x 2160, ALPR cannot read the data. The image is grainy, and nothing is visible until switching back to the recommended 1080P. Even then at 1920*1080, you get a grainy picture when motion is detected. To lower it slightly to 1280*960 will increase the capture ability of Open ALPR.

I will lower the frame rate to 15 FPS. Good idea
 
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