Canon’s interchangeable lenses for interchangeable-lens digital cameras, such as digital SLR (single-lens reflex) and digital cinema cameras, are realized through advanced proprietary technologies and know-how. This page introduces some of the technologies incorporated in the EF lens lineup.
Lens Coating Technology Created by Nanotechnology
The reflection of light from the lens surface causes flare and ghosting. In the past, the surface was coated with a thin film to control reflected light, but it could not be sufficiently controlled in some cases depending on the angle of incident light.
SWC developed by Canon is a new type of technology for preventing reflection by using an array of countless wedge-shaped nanostructures smaller than the wavelength of visible light arranged on the lens surface to control the reflection of light. As there is a smooth transition between the refractive indexes of glass and air, it is possible to eliminate the boundary between substantially different refractive indexes, which enables significant control over the occurrence of reflected light. It is also very effective with light that has a large angle of incidence, which could not be controlled using conventional coating.
A Compact, Reduced-Weight Telephoto Lens
The Diffractive Optics (DO) lens for SLR cameras is designed to utilize the opposing chromatic dispersion patterns of diffractive and refractive optical systems built into the lens. Canon has applied optical principles to substantially reduce both the size and weight of this telephoto lens for SLR cameras. (EF400mm f/4 DO IS USM)
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