Maintaining the outstanding performance at max aperture of the much superior f/2.8L but in a compact size, the EF 70-200mm f/4L USM Lens from Canon is a professional zoom telephoto appropriate for a wide range of applications from portraiture to sports. It is fully well-suited with the Extender EF 1.4x II and 2x II tele-converters (requires f/8 AF sensitivity with EF 2x II).
Similar to every autofocus Canon "L" lens, the EF 70-200mm f/4LUSM produces optical performance equivalent to related fixed focal length lenses, having quiet, high-speed ultrasonic (USM) focusing and permanent manual focus override capability. A focus range restraining option also allows rapid autofocus rates.
Distortions and aberrations are extremely tiny for a lens of such capacity. This lens joins 1 artificial fluorite element with two UD (Ultra-low Dispersion) elements which are helpful in achieving images free of secondary spectrum aberrations that are often the curse of consumer-grade telephoto zooms. It is lighten enough to not require a tripod collar (86 percent lighter than EF 70-200mm f/2.8L), but for handling functions there is an optional tripod collar.
The min distance of focusing is 3.9' (1.2m) in its entire range of focal lengths, and it accepts 67mm screw-in filters.
Note: This lens doesn’t have seals for moisture and dust resistance.