Used to eliminate specular reflections and hot spots, Circular Polarizers in rotating mounts allow maximum flexibility and ease of use. However in most machine vision applications we recommend the use of linear rather than circular polarizers. Circular polarizers are recommended for eliminating glare from spherical surfaces or in cases where an auto-focus or metering system are used involving a beamsplitter or mirror mounted in the optical path inside the camera.
Best results are achieved when circular polarizing film is also used over the light source. Left-handed and right-handed polarization directions are available.