Heat Shield Coating - RF Lens World - Canon India

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    Heat Shield Coating

    Heat Shield Coating

    Canon’s efforts to address heat accumulation, with our traditional white-barrel lenses, have reached a new stage. To ensure that its lenses maintain outstanding optical performance when used in hot, direct sunlight, Canon adopted a heat-reflecting white coating for the barrel of some lenses, rather than the more traditional black. The history of white-barrel lenses stretches back to the FD600mm f/4.5 S.S.C and FD800mm f/5.6 S.S.C., two large-aperture telephoto lenses released in 1976 for single-lens reflex (SLR) cameras.* Canon’s in-house efforts to develop heat shield coatings originated as a way to make lenses more reliable under high temperature conditions. Through trial-and-error research into the selection and composition ratio of coatings Canon identified ways to enhance reflectivity toward light in the infrared spectrum, and developed new technologies to suppress temperature increases in both the coating film and the coated items. The final result is a series of white-barrel lenses that offer greater reliability when shooting in the hot sun.

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    Our heat shield coating uses infrared-reflecting pigments to enhance reflectivity against the “heat” component of sunlight. In the past, Canon lenses have offered either a carbon black or a white titanium oxide surface coating. However, carbon black strongly absorbs infrared waves, offsetting some of the reflectivity improvements offered by the heat shield coating. Our newly developed heat shield coating enhances reflectivity by replacing carbon black with an infrared-reflecting pigment. The coating also uses titanium oxide with a silica covering, making it more resistant to UV weathering. It is highly resistant to damage caused by scratching or abrasion. Lenses with the new coating retain Canon’s signature “white-barrel” color. Heralding in a new age for white-barrel lenses, the Canon heat shield coating was first introduced in the EF400mm f/2.8L IS III USM and EF600mm f/4L IS III USM, and is now used in all RF lenses with a white body.

    *For single lens reflex cameras lenses. Also used in the TV2000mm f/11 super telephoto lens for broadcast cameras, launched in 1960.

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