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 its 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.
• Super Spectra coatings ensure accurate color balance and high contrast.
• Magnesium alloy construction keeps its weight comparable to shorter telephoto lenses.
• Full-time manual focus override
• AF Stop function shuts off autofocus when obstruction appears
• Two-stage image stabilization, dual-axis camera shake correction or vertical axis only (for panning)
• Focus preset function allows for returning to a specifically set focus by turning a ring in front of the focus ring
• Circular aperture produces attractive background defocus