The Canon EF 800mm f/5.6L IS USM Autofocus Lens is currently
Canon's longest telephoto lens, and an excellent choice for any
long-distance application, e.g. outdoor sports, wildlife, news
photojournalism, and so on. Even though it has a long 800mm focal
length, the magnesium alloy used in the construction for this lens makes
it lighter then the 600mm f/4L lens, weighing in at less than 10 lbs
(4.5kg).
This lens shares the same lightweight, weather-resistant construction as
the rest of the IS Super Telephoto lenses, as well as their improved
control layout, improved weight distribution, and mechanical manual
focus. Its IS Image Stabilizer mechanism allows the use of shutter
speeds up to 4 times slower with no perceptible increase in image blur.
For optimum visual performance, the lens incorporates four types
of special optical elements: aspherical elements to correct spherical
aberrations, and refracting Fluorite, UD and Super UD (ultra-low
dispersion) elements to eliminate secondary chromatic aberrations.
