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Canon FL 300mm lens refers to two telephoto prime lenses made by Canon. The lenses have an FL type mount which fits the Canon FL line of cameras. First introduced in 1969, the FL lens replaced the R mount version, which in turn was superseded by its FD equivalent. Altogether, two variations (with two different aperture settings) were made in its short production life. The FL-F 300mm f/5.6 was the world's first lens to use synthetic fluorite crystals in its elements; those are commonly found today in its L lens.〔(Cannon camera story ). Cannon Museum〕 The f/2.8 model was used to take photographs of Henry Kissinger reading a confidential document at the Helsinki Accords. The images were so sharp that the text could be read clearly. ==Information== The f/5.6 FL-F was the first interchangeable lens to use calcium fluoride (CaF2) on its lens elements to achieve extremely high contrast correcting chromatic aberration. It used two fluorite elements. The main benefits of fluorite on lens is its low index of refraction and low dispersion is superior to that of optical glass. Though its optical glass wavelengths in the range from red to green is similar, it differ greatly for wavelengths in the range from green through blue, enabling a significant improvement of the imaging performance of super-telephoto lenses in terms of sharpness, contrast and color balance.〔 The f/5.6 FL-F are primarily designed for shooting sports, wildlife, and candids. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Canon FL 300mm lens」の詳細全文を読む スポンサード リンク
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