Super Spectra Coating - RF Lens World - Canon India

Super Spectra Coating

Canon has identified four factors that need to be met in order to make the ideal photographic lens:

1. Light rays from a single point on the subject should converge on a single point after passing through the lens
2. Any flat surface perpendicular to the optical axis should be reproduced as a flat surface
3. Any flat object perpendicular to the optical axis should be reproduced identically, without distortion
4. Colours of the subject must be reproduced accurately.

This final requirement is one that Canon itself singled out as a major development objective. In this quest, Canon established its own standard for uniform colour reproduction in the 1960s, when professional photographers first began using colour reversal film. Canon started with the assumption that any lens should deliver the same colour reproduction. But to evaluate colour precision, it is necessary to establish some criteria for colour reproduction and balance.

Canon began by studying the characteristics of sunlight, and in particular the changes in light over the course of a year, as air quality and the angle of the sun varies. In addition to repeated test photos, Canon solicited feedback from numerous panelists. The data accumulated in this process was then converted into numeric values, to eventually establish Canon’s own colour reproduction standard for lenses. In the 1980s, when the photographic industry introduced the ISO Colour Contribution Index as the industry standard, they adopted values virtually identical to those already being used by Canon, though Canon’s standards are a bit stricter, with less tolerance for variations.

Super Spectra Coating (SSC) technology was developed to help Canon meet this strict colour reproduction standard. This multi-layered coating creates a hard, durable lens surface with stable characteristics, and reduces the chances of lens flare and ghosting caused by reflections on the lens surface. When used on digital cameras, which are especially susceptible to lens flare and ghosting, Super Spectra Coating delivers optimumal colour balance. Efforts to optimize coating performance continues, as Canon strives to respond to changing times and meet the changing requirements of professional image makers.