October 23 2007
Canon displayed prototypes of two new high performance telephoto lenses for its EOS Digital SLR camera range at the Expo.
The new EF200mm f/2L IS USM and EF800mm f/5.6L IS USM, are part of Canon’s L -series lenses. Both incorporate high-performance Image Stabilization and feature optical systems utilizing special optical materials, such as fluorite to correct chromatic aberrations, making possible high-resolution, high-contrast shooting performance.
According to Canon the L stands for Luxury and is their premium line of interchangeable lenses for their SLR cameras. This seems rather a strange terminology as the L series is acknowledged as their no compromise high performance lenses, where luxury considerations such as comfort and convenience take second place.
What the Pros look for in lens.
The performance criteria emphasized by Canon when they talk about the lenses is a good indication of the important areas for professional photographers.
Particularly with long focal length telephotos, any form of camera movement is very noticeable in the image. News and sports photographers may only get one chance at the decisive moment in an event, so anything that improves their chances of a successful shot is very desirable. It is not always practical to use a tripod or monopod, so image stabilization performance is a key issue.
This is all about sharpness of the resultant image. Commonly abbreviated to CA, Chromic Aberration is where the various colors in the light separate during refraction in a lens element, as in a prism.
To combat this lens makers use special glass, and this case Cannon say they use, “special optical materials such as fluorite to correct chromatic aberrations, making possible high-resolution, high-contrast shooting performance.”
Other lens makers term this ED or Extra low dispersion glass.
CA results in a slight fringing in a colored halo effect around the edges of objects or lines in the image.
EF200mm f/2L IS USM
This lens targets professional photographers seeking a brighter lens for portraiture and indoor sports photography, with a large maximum aperture of f/2. These are sometimes referred to as fast lenses and are highly prized by photographers.
The large aperture is important for composition and autofocus performance as the lens diaphragm is usually at maximum aperture until the shutter is pressed. Photographic autofocus systems work by comparing the contrast between sections of the image. In lower light, the contrast is not so obvious so the focusing system can be slow, or not work at all.
The large aperture helps the focusing system work in situations where a lens with a smaller maximum aperture may not focus reliably.
EF800mm f/5.6L IS USM
This lens promises to become a favourite for professional Canon users in sporting events around the world. Canon says its performance will surpass their current top of the line 600mm super telephoto.
Canon said they developed it in response to requests from users working in the fields of sports and news photography looking for a high-performance lens that offers a longer focal length. All important where access is restricted.
“These new lenses demonstrate that Canon is continuing to respond actively and flexibly to the wide-ranging needs of professional and advanced amateur users, with the aim of contributing to the expansion of photographic possibilities for SLR cameras,” said Yuichi Ishizuka, senior vice president and general manager, Consumer Imaging Group, Canon U.S.A.