Nano Coating
A coating built from structures smaller than the wavelength of light, creating an extremely low refractive index layer that almost eliminates reflection.
In depth
Conventional coatings work well for light arriving straight on but lose effectiveness at oblique angles. Nano-structured layers — sold as Nano Crystal, SubWavelength Structure or Air Sphere coating — maintain their performance across a wide range of incidence angles, suppressing the ghosting that appears when a bright source sits just outside the frame.
Examples in practice
Shooting into a low sun, a nano-coated wide-angle shows a clean gradient where an older lens would scatter green ghosts across the frame.