Q: Do you know the optical range for the reader?
The sweet spot for plate reads is 1.5 to 2.5 meters between camera and plate.
Also check to make sure the lens is clean.
Another issue may be camera angle.
Optimum angle for the camera is straight on (parallel) to the plate
The camera allows the adjustment to the reading box. It is the first 4 text boxes on the Plate Reader Settings. Then when you go to the camera preview you can see the red box which represents those values. The best would be to have the box close to the bottom, and I have found that you don't want it right on the edge.
The left side and right side are the same; check to see what the camera is seeing. You can do this by looking at the Frame Grabber Settings screen. ( Camera OCR )
The result was the following: The box is smaller so in fact the read will be faster since we are restricting what area the software has to interpret. Less to scan, faster read.
I set this plate about 4 meters from the camera about 3 feet off the ground to simulate a truck plate that would be higher up.
Cars would definitely be about half that high but as you can see this reduced capture box would accommodate either position.
Frame Grabber Settings
Make sure that all camera options are auto.
On the Handheld
For NOREADs you can check the setting in System Settings to see if that can be reduced.
It may mean more noise, but it may also help with determining what is going on (ie. reading but not seeing it as a READ result)
To adjust this setting go into system settings and tap on Include NOREAD (ie. vanity) Results
Set the percentage to 50% to start. We can tweak it once we see how the system reacts.