I’m testing a vision camera and analyzing the level of dirt on copper plates using a pixel counter function.
Since the plates are copper, there is light reflection. Without using a light source, the scene is too dark to see properly, but using a light causes reflections. Do you have any suggestions on how to set up the light bar to improve the image quality?
Based on your image and the challenge with copper plate inspection, here are several practical lighting strategies to reduce reflections while maintaining good visibility:
Diffuse Dome Lighting
Use a dome light diffuser that surrounds the inspection area
Creates even, shadowless illumination from multiple angles
Minimizes specular reflections from copper surfaces
Polarized Lighting
Install cross-polarized filters (one on the light source, one on the camera lens at 90°)
Effectively eliminates direct reflections while preserving surface detail
Ideal for metallic surfaces like copper
Low-Angle Dark Field Lighting
Position lights at very low angles (nearly parallel to the copper surface
Highlights dirt/defects while minimizing direct reflections into the camera
Works well for detecting surface contaminants
Diffused Ring Light with Angle Adjustment
If using a ring light, add a diffusion filter
Angle the light bar at 30-45° rather than perpendicular
Consider using multiple lower-intensity lights instead of one bright source
When you do not use the light source af the camera, and use the environment light instead then remember to have really high exposure times as the environment light is so low intensity compared to the flash light of the camera.
