This application involves PCB with clear flux on copper leads. The first image is the original color image while the second image is the monochrome application example. The second image (before) is the monochrome application image without polarization filtering. Notice the copper leads on PCB reflect light, making clear liquid flux detection nearly impossible. The final image (after) shows the clear flux detection is made possible with MidOpt® PS007 Polarizer Film used over the DCM High Powered Ring Light and a MidOpt PR032 Polarizer Filter over a 35mm Lens.

Filters used:
PR032 Linear Polarizer
PS007 High Contrast Linear Polarizer Film