I bought the lens for a safari trip. I wanted an easy to use and lightweight lens and this fulfulled my needs. Too bad the lens is not dustproof. Africa is like riding on a dirt road at best.
The Canon EF-S 55-250mm IS telephoto Zoom Lens is designed with Canons Optical Image Stabilizer technology while retaining compactness and lightness in response to demands of photographers. This high zoom ratio lens is equivalent to a focal length of 88-400mm in the 35mm format (when used on Canon EOS cameras compatible with EF-S lenses) and the image stabilizer effect equivalent to a shutter speed about 4 stops faster than the same size lens without Image Stabilizer. In other words if the slowest shutter speed you could formerly hold a 250mm lens steadily was 1/250th of a second with Canons 4-stop stabilization correction you could hand-hold at shutter speeds as slow as 1/15th of a second. It also uses a UD-glass lens element to correct chromatic aberration for excellent image quality throughout the zoom range. Key Features: 55-250mm f4.0-3.5 Telephoto High-Performance Lens with a telescopic range covering a zoom range equivalent to 88 to 400 mm With 12 elements in 10 groups including UD glass elements are used to correct chromatic aberration for excellent image quality throughout the zoom range. Best-in-class f4.0-3.5 brightness and high picture quality combine to ensure high imaging performance with improved sharpness and contrast all over the zooming range. An improved lens coating reduces glare when shooting against the light and minimizes ghosts and flare. In addition with coverage that extends to the super-telescopic domain equivalent to 400 mm on a 35 mm camera lens this lens makes it possible to capture the motion of a distant subject or take spectacular landscape images by taking advantage of the compression effect produced by telescopic lens. EF-S Mount A derivative of the EF lens mount created for a subset of Canon digital single-lens reflex cameras with APS-C sized image sensors. Cameras supporting the EF-S mount are backward-compatible with the EF lens mount. The S in EF-S stands for short back focus which means that the rear element of the lens is closer to the image sensor than on regular 35 mm SLR cameras. The proximity of the rear element to the image sensor greatly enhances the possibilities for wide angle and very wide angle lens enabling them to be made smaller lighter (containing less glass) and faster (larger aperture). Close-Up shooting from as close as 1.1 m throughout the zoom range The focusing system uses floating and inner focusing mechanisms to provide a minimum shooting distance of 1.1 m throughout the zoom range. With a maximum shooting magnification of 0.31x (equivalent to 0.42x on a 35 mm camera lens) this lens out-performs any other in its class (large-aperture zoom lenses capable of covering the super-telescopic domain). This powerful close-up capability makes it easy to capture close-ups of blossoming flower or a resting butterfly that would fly away if you approached too closely. Image Stabilizer Technology (IS) for ultra-fast autofocusing Camera shake causes lens movement during image exposure which shifts the angle of incoming light relative to the optical axis and results in blurred images. Canon IS Lenses correct for camera shake by shifting certain optical components in inverse relation to the lens movement. This maintains the position of incoming light rays on the film or capturing element and helps prevent blur caused by camera shake. Circular Aperture Mechanism The circular aperture makes it possible to create a smooth uniform aesthetically pleasing blur.