Material Affects Lighting Setup
A key step in developing the illumination strategy for any machine vision application is to determine how the component being inspected will reflect and transmit light. Some aspects of this are fairly basic. If the material is opaque, frontlighting may be needed (see figure). If it is translucent or transparent, backlighting tends to be the better option. However, each case may require a different backlighting strategy to enhance contrast.
In a typical arrangement of lights, camera, lens and...
Photonics Spectra, May 2004