Which lens assembly contains the "minus-blue" coating that filters out light from the aircraft instrument panel?

The objective lens is the component of night vision goggles that contains the "minus-blue" coating. This specialized coating is crucial because it filters out specific wavelengths of light emitted by aircraft instrument panels, which tend to be in the blue region of the spectrum. This filtering is important for maintaining the user's night vision and preventing distraction or discomfort from bright light sources that could interfere with operational capacities.

In the context of night vision, the objective lens gathers ambient light and focuses it onto the image intensifier tube. By reducing the blue light interference, the objective lens ensures that the clarity and effectiveness of the night vision optics are maximized, allowing the user to have a clearer view in low-light conditions. This capability also helps to preserve the user's ability to see other critical visual cues in the night environment.

The other components, such as the eyepiece lens, merely magnify the intensified image, while the image intensifier itself is involved in converting the light into a visible image and does not feature any coatings. The protective cover serves a different purpose by safeguarding the goggles but lacks any optical functions.