Super Spectra Coating
When light enters a lens, a small percentage is reflected off the internal lens element surfaces. This reflected light, if not dealt with effectively, can result in distortion of the recorded image.
There are two common types of image distortions: Ghosting, in which a faint second image appears on the photo; and flare, which occurs when light from the back of the lens barrel is reflected onto the image.
Light travels in waves – since each colour travels at different wavelengths, multi layers coatings are required to effectively reduce reflection. Each layer works on different wave lengths of light. Canon's multi layer Super Spectra coating allows up
to 99.9% of light through to the CMOS sensor, over a range that extends from ultra violet to near-infrared light. As well as minimising ghosting and flare, Super Spectra Coating ensures a consistent colour balance across all EF lenses and plays a key part
in delivering the sharp, high-contrast results that Canon lenses are renowned for.