It is likely that direct sunlight or other bright (brighter than the screen during calibration) light falls into the camera's field of view - the program works on them in the same way as on laser hits.
Make sure that the work surface is not exposed to any other light than the projector and the laser spot from the weapon.
Another mistake may be calibrating the camera with the lighting turned off or less illumination than at the time of use, such a calibration will lead to the installation by the program, at the time of calibration, of an insufficient (low) response threshold, because the maximum brightness of the working surface at the time of calibration was lower than at the time of use.
To avoid this error, calibrate the camera under the lighting in which you plan to use the shooting range.
The same situation may occur if you use glossy or dark (black) surfaces as a screen for the projector, which reflect the light of the projector unevenly.
The optimal solution would be:
- Project an image onto a white matte surface.
- Calibrate the camera under the lighting in which it is planned to use the shooting range.