Application of Tsingcarbo Light-Absorbing Coatings on Lens Barrels

Stray light is a fundamental challenge in any optical system. When light passes through a lens assembly, a portion inevitably strikes the inner walls of the lens barrel. If those walls are even moderately reflective, the non-image-forming light bounces around inside the barrel and eventually reaches the image plane. The result is a loss of contrast, veiling glare, ghost images, and a general degradation of resolution and detail.

The physical principle behind stray light suppression is simple: turn the barrel interior into an optical “black hole” by applying a coating that absorbs rather than reflects. The ideal light-absorbing material must have extremely low hemispherical reflectance across a broad spectral range, high absorptivity, and the ability to conform to tight or complex geometries.

Tsingcarbo Light-Absorbing Coatings from Suzhou Tsingcarbo Nanomaterials Co., Ltd. provide a state-of-the-art solution. Engineered by a team from Tsinghua University, these coatings achieve a hemispherical reflectance below 1% from the ultraviolet to the near-infrared (200–2500 nm), meaning over 99% of incident stray light is absorbed on first contact.

To accommodate different lens barrel designs, two processing methods are offered:

For large-diameter barrels: The preferred method is adhesive-backed Tsingcarbo film. At only ~0.4 mm thick, the film is flexible, can be cut to shape, and applied directly to flat or gently curved inner walls. This method delivers maximum absorption (>99%) and is ideal for most standard optical assemblies.

For small-diameter barrels: When the inner diameter is too narrow for film application (e.g., deep, confined cavities where tools cannot enter), Tsingcarbo Light-Absorbing Coatings can be applied via precision spray coating. This process deposits a uniform, highly absorbing layer directly onto the inner wall, achieving >98.5% absorption while maintaining excellent cleanliness and adhesion.

Both methods are free of particulates, outgassing, and volatile organic compounds, making them safe for high-precision optical systems. By turning every lens barrel into a true dark chamber, Tsingcarbo coatings ensure that the final image carries nothing but pure signal.

For more information, please contact Suzhou Tsingcarbo Nanomaterials Co., Ltd.