Retaining the excellent performance at maximum aperture of the much larger f/2.8L IS but in a smaller and more travel-friendly size, the Canon EF 70-200mm f/4L IS USM Lens is a professional zoom telephoto suitable for a broad range of applications from sports to portraiture. It is fully compatible with the Extender EF 1.4x II and 2x II teleconverters (requires f/8 AF sensitivity with EF 2x II), and its built-in image stabilizer allows the equivalent hand-holding ability of a shutter speed 4 steps faster-making this a great lens for capturing still subjects with a telephoto perspective in very low light. The stabilizer can be activated to only correct shake in the vertical axis for panning action when desired as well.
Like every autofocus Canon "L" lens, the EF 70-200mm f/4L IS USM delivers optical performance equal to similar fixed focal length lenses, with silent, high-speed focusing and full-time manual focus override capacity. Distortions and aberrations are remarkably small for a lens of such capability. This lens combines 1 artificial fluorite element with 2 UD (Ultra-low Dispersion) elements to help achieve images free of secondary spectrum aberrations, which are often the bane of consumer-grade telephoto zooms. Its aperture diaphragm is circular, to help create very natural out-of-focus background highlights.
This 70-200mm lens has a minimum focusing distance of 3.9' (1.18m) throughout its entire range of focal lengths, and it accepts 67mm screw-in filters.