Canon lenses are reknowned for their performance and optical quality. And no lenses have a better reputation among professional photographers than Canon's L-series lenses. Identifiable by a distinctive red ring around their outer barrel, these lenses use special optical technologies Ñ Ultra-low Dispersion UD glass, Super Low Dispersion glass, Fluorite elements, and Aspherical elements Ñ to truly push the optical envelope.
L-series telephoto lenses utilize Canon's UD glass to minimize the effect of chromatic aberration, sometimes called color fringing. UD glass provides outstanding contrast and sharpness in lenses like the 70-200 f/2.8L IS and 300mm f/4.0L IS. Even more effective are fluorite elements, used in high-end super-telephoto lenses like the EF 300mm f/2.8L IS and 400mm f/2.8L IS. A single fluorite element has the corrective power of two UD glass elements, which gives these L-series lenses their spectactular performance.
Wide-angle lenses and fast normal focal-length lenses often suffer from another optical problem Ñ spherical aberration Ñ which causes an overall softening and optical "smearing" of the image. Canon has developed four different manufacturing technologies to produce Aspherical lens elements, which combat this problem. Aspherical optics, which have an extremely precise variable curvature of one or both sides of a lens element, also allow more compact lens designs and permit lighter lenses with fewer elements. Combined with Canon's exclusive multi-coating technology, Super Spectra Coating, and the attention paid to details such as anti-reflective material inside of lens barrels, L-series lenses virtually eliminate internal ghosting and flare.
Many EF telephoto lenses are white, to reduce the amount of internal heat build-up during long shooting in bright sunlight. And the new Image Stabilized super-telephoto L-series lenses add extensive dust-and moisture-resistant seals and gaskets, enabling pros to keep shooting in the worst conditions.
Canon L-series EF lenses are designed and built to meet the needs of the most demanding professional photographers. Their superb optics enable pros and advanced amateurs to have lenses that are the absolute pinnacle of optical performance, and enable lens/speed combinations with professional performance simply not attainable using traditional optical technology.
http://www.usa.canon.com/eflenses/technology/lseries.html
I don't have any "L" lenses yet and I am looking into a couple. I
just started shooting with canon this year and don't know the
history behind it.
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Pbase supporter
Brian
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A Canadian in the US-EH.
