In this example we see beer bottles imaged at the same time, which have dark, specular, cylindrical surfaces that are difficult to image because the labeling tends to produce glare regardless of how the bottles and lighting may be setup. Polarizing filters used over the lens as well as the light source significantly reduces the specular glare from the application. In addition, because of the curved shape of the bottle, ambient light is also contributing to the glare. Using a MidOpt BP635 Light Red Bandpass filter together with a 625nm red LED effectively eliminates the glare entirely.

Filters used:
PR032 Linear Polarzier
PS030 Ultra High Contrast Linear Polarizer Film
BP635 Light Red Bandpass Filter