A long-reaching zoom characterized by its versatility, the EF 200-400mm f/4L IS USM Extender 1.4x from Canon is a medium to super-telephoto distinguished by its unique optical design and fast performance. Featuring a built-in 1.4x extender, you can quickly and intuitively switch between the native 200-400mm f/4 setting and an effective 280-560mm f/5.6 for greater reach. Benefitting this unique design is a sophisticated optical layout, which includes one fluorite element and four ultra-low dispersion elements to control chromatic aberrations and color fringing for increased clarity. A Super Spectra coating has also been applied to individual elements to reduce lens flare and ghosting for greater color accuracy and contrast when working in bright or backlit conditions.

Beyond the optical attributes, this 200-400mm f/4 is also characterized by its advanced four stop-effective Image Stabilizer system, which has three separate stabilization modes to suit various shooting applications. Also complementing handling is a sophisticated ring-type USM, which provides quick, quiet, and accurate autofocus performance along with full-time manual focus override. Additionally, this lens is weather-sealed for use in trying environmental conditions and it has a removable rotating tripod collar to benefit working atop a tripod or monopod.

• Super telephoto zoom is designed for full-frame Canon EF-mount DSLRs, however can also be used with APS-C models where it provides a 320-640mm equivalent focal length.
• Built-in 1.4x extender allows you to instantly extend your reach to 280-560mm (or 448-896mm equivalent with APS-C cameras) simply by flipping the left-hand switch. Since the extender is integrated within the lens housing, it is optically matched to the lens for improved imaging performance and also fully maintains the lens's weather sealing.
• Constant f/4 maximum aperture, without the teleconverter in position, offers consistent illumination throughout the zoom range. When the 1.4x teleconverter is engaged, the maximum aperture is effectively f/5.6.
• One fluorite element and four ultra-low dispersion elements are used to greatly reduce color fringing and chromatic aberrations in order to achieve greater clarity and color accuracy.
• Super Spectra coating has been applied to individual elements to minimize ghosting and flare for greater contrast and color neutrality when working in strong lighting conditions.
• An Optical Image Stabilizer helps to minimize the appearance of camera shake by up to four shutter speed stops to better enable working in low-light conditions and with slower shutter speeds. Three distinct IS modes are available: standard single-shot mode, a panning-optimized mode, and a mode that only activates the Image Stabilizer during the exposure.
• A ring-type Ultrasonic Motor (USM), along with optimized focusing algorithms and a high-speed CPU, is employed to deliver fast, precise, and quiet autofocus performance as well as full-time manual focus override.
• Focus Preset function is available to quickly recall a programmed focusing position.
• Focus Limiter switch lets you constrain the focusing to different ranges for faster performance to suit different applications.
• A Power Focus setting is available, and allows you to electronically and smoothly adjust your focus position to suit video recording. This setting utilizes a dedicated ring in front of the main focusing ring and allows you to use one of two different focusing speeds.
• Rounded nine-blade diaphragm contributes to a pleasing out of focus quality that benefits the use of shallow depth of field and selective focus techniques.
• As a member of the esteemed L-series, this lens is sealed against dust and moisture for working in inclement environmental conditions.
• Fluorine-coating on exposed elements affords protection to the optical system, resists smudging and fingerprints, and is easier to clean.
• Removable rotating tripod collar is included and benefits working with the lens atop a tripod or monopod.
• Compatible with optional EF 1.4X and EF 2X teleconverters.