The Canon EF 70-200mm f/4 L IS USM is a profesional grade telephoto zoom lens. Designed to deliver top quality images without as much bulk, weight or expense as a comparable f/2.8 zoom would require the 70-200mm f/4 L IS USM gives demanding photographers another option; a Pro's choice no longer needs to be between a 3lbs. professional tele-zoom and the disappointment of a lesser quality lens.
Being an L series lens maximum attention was been given to sharpness, color reproduction and bokeh by the designers. The heart of the lens is an optical system consisting of 20 elements in 15 groups; Two Ultra Low Dispersion UD glass elements and one Flourite glass element are strategically placed to maximize image quality. All lens elements are free of lead.
The constant f/4 maximum aperture allows reasonable background blur and with advancements in camera ISO noise levels, fast shutter speeds are getting easier to find. Weighing in at just over pound and a half, user fatigue is lessened and hand held photography becomes easier. Canon's optical Image Stabilization system provides additional aid to handheld shooting, sensors detect shake or vibration and a special set of elements moves in real time to offset the path of light to compensate for lens shake. The Image Stabilization movement mechanism is an upgraded design from earlier Canon IS lenses enabling faster smoother movements, allowing up to four stops worth of stabilization. A photographer previously using a shutter speed of 1/1000 of a second may now be able to get similar stability at 1/60th of a second. The image Image Stabilization system has two modes: Mode One designed for stationary subject matter and Mode Two designed for panning along with a moving subject. An On/Off button is also provided to save power and for when the lens is mounted on a solid support like a sturdy tripod. A rotating lens tripod mount is available as a separate accessory and greatly aids vertical shooting from either a tripod or monopod.
Portrait Photographers, sports photographers, pet photographers, wedding photographers, photojournalists, wildlife photographer, other action photographers and nearly everyone else wants fast autofocus and Canon delivers it with an internal focus system connected to a ring type Ultrasonic Motor. The focus mechanism is designed to provide the photographer the option of instant manual focus override without touching the lens AF control button, manual focus override works full time (even without power to the lens). The zoom and focus grips have different patterns and widths to aid tactile differentiation. A focus limit switch allows selection of a narrower 3 meters to infinity focus range to significantly reduce autofocus time as closer focusing distances occupy an amount of focus travel that is proportionally much greater than in farther focus distances. The full focus range of the lens is 1.2 meters to infinity.
The lens features environmental sealing to make it resistant to dust and moisture. While compatible with Canon L Series EF 1.4x and EF 2x tele extenders, autofocus points need to be sensitive to an effective aperture of f/8 to work with a 2x tele-converter combined with an f/4 lens.
EF 70-200mm f/4L IS USM Lightweight, compact L Series telephoto zoom lens with Image Stabilizer. Provides up to an incredible four stops of shake correction. Fluorite UD lens elements provides excellent optical performance. Water and dust-proof construction. The EF 70-200mm f/4L IS USM is a lightweight, compact L Series telephoto zoom lens with Image Stabilizer. The optical Image Stabilization in the new EF 70-200mm f/4L IS USM lens provides up to an incredible four stops of shake correction-a first for Canon IS lenses. The use of fluorite UD lens elements provides excellent optical performance in terms of resolution and contrast. These features, together with its water-and dust-proof construction, provide both the performance and portability to meet user demands.