Sigma 18-35mm f/1.8 DC HSM - Art Series Lens for Canon

Truly a revolutionary product, the Sigma 18-35mm 1.8 DC HSM is the first wide-angle to standard zoom lensZOOM LENSAllows a camera to, unlike a fixed-focal length or prime lens, change smoothly from a long shot to a close-up or vice versa by varying the focal length. A true zoom lens, also called a parfocal lens, is one that maintains focus when its focal length changes. Due to more moving parts, zoom lenses often produce images of slightly lesser quality than their prime lens counterparts. However due to the inherent flexibility of being able to vary the focal length, they are extremely popular for photography where composition needs to be adapted quickly - such as at weddings, for example. to achieve a large apertureAPERTUREAperture, shutter speed and ISO form what is known as the exposure triangle in photography. Aperture refers to an opening inside the lens, similar to the iris of your eye, that changes in diameter to control the amount of light that enters a camera. Aperture is expressed in f-stops: the lower the number, the larger the aperture, e.g. f/1.4 is larger than f/8. A larger (or wider) aperture allows more light to pass through the lens to the sensor (film) as a picture is taken, particularly useful in low-light conditions. A larger aperture also produces a shallower depth-of-field, and thus more background blur. of f/1.8. Designed specifically for APS-C sized sensors, the Sigma 18-35mm f/1.8 translates to 27mm-52.5mm on 35mm camera. Tapping into Sigma’s long history of lens innovations, the 18-35mm f/1.8 DC HSM incorporates a wide glass molded aspherical lens with Special Low Dispersion (SLD) glass to compensate for aberrations and curvature at the widest angle. Internal focusing and zooming allows for more usability and functionality. The 18-35mm is ideal for landscapes, portraits, still life, snap shots, casual, and close-ups and the Hyper Sonic Motor (HSM) ensures smooth, fast and accurate autofocusing. The use of Thermally Composite Material (TSC) reduces size and weight but increases the lens durability. Its new Global Vision design works with its compatibility with the Sigma USB dock for further customization. A 9 blade rounded diaphragm also creates beautiful background blur. The Sigma 18-35mm f/1.8 DC HSM is a new benchmark in photographic history and a must have for every camera bag.