This is the longest telephoto lens among Canon's lineup, and a terrific choice for any long-distance application-outdoor sports, wildlife, news photojournalism, and so on. It's actually lighter than Canon's EF 600mm f/4L IS lens, weighing just under 10 lbs. It uses a refined optical design, with two fluorite lens elements, one UD element, and one Super-UD-glass element, for outstanding correction of color fringing and superb contrast and sharpness. This super-telephoto lens uses magnesium-alloy barrel construction to enhance its light weight, and has weather-resistant gaskets throughout for use in harsh conditions. It's compatible with both the EF 1.4x II and 2x II tele extenders for even more reach: EOS cameras with 45 AF points will continue to provide autofocus at the center AF point when the lens is used with the 1.4x extender. Finally, it's image stabilized, providing up to 4 stops of correction for camera shake. This makes it even more practical in many situations.

Technical Details

-The Canon EF800mm f/5.6L IS USM, which is a L (Luxury) series lens incorporating a high-performance Image Stabilizer
-Feature optical systems utilizing special optical materials such as fluorite
See more technical details

 "Took The Plunge" 2009-05-05
By W. Giordano (florida keys)
Had the Canon 500mm f 4.0 super telephoto and was very satisfied with the superb quality but found I needed more reach without using the 1.4x and 2x teleconverters. Having to change converters in the field, with weather and huimidity being what it is here in south Florida concerned me.
With the bare lens I can achieve the same result as I did with the 500mm without fumbling to attach the converters on the fly.
Just a note: Some may disagree, but I saw no discernable I.Q. degradation from the 1.4x converter when attached to the 500mm. With the 2x there was a slight softness at long range.
I use the 800mm with a Canon 50D and Canon 5d MarkII with wonderful results.
The drop-in 52mm circular polarizing filter[accessory] provides gorgeous color contrast and saturation during cloudless sunny daytime use.
Super fast auto-focus with two IS settings that help keep this large lens functioning in windy conditions.
Another note: This lens will auto-focus fast with the aforementioned camera bodies but will not auto-focus if a 1.4x converter is attached, although the IS will function. You would need to use a 1D or 1Ds series body to have auto-focus function with the 1.4x converter and then it would only utilize the center focus point. Auto-focus will not work with "any" camera body with the 2x converter attached to this lens....
Have taken some great wildlife shots down here in the Everglades and Florida Keys and hope to get to use this amazing lens in other locales soon


Read more Canon EF 800mm f/5.6L IS USM Super Telephoto Lens for Canon Digital SLR Cameras

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