What material are lenses for thermal cameras typically made from?

Lenses for thermal cameras are typically made from germanium because of its unique optical properties, particularly in the infrared spectrum. Unlike conventional lenses made from glass or plastic, which do not transmit infrared radiation effectively, germanium allows for the passage of infrared wavelengths, making it ideal for thermal imaging applications.

Germanium has a high level of transmission in the infrared range (specifically around 8 to 14 micrometers), which is crucial for detecting and visualizing heat signatures accurately. This capability enables thermal cameras to detect temperature differences in the environment, making them invaluable in a variety of applications, such as surveillance, firefighting, and medical diagnostics.

The other materials mentioned, like glass and plastic, are not suitable for thermal imaging because they absorb infrared radiation instead of transmitting it. Silicon, while used in some electronic applications, also lacks the desired infrared optical properties required for effective thermal imaging lenses. Therefore, germanium stands out as the correct and most appropriate choice for thermal camera lenses.