Sigma 10-20mm f/4-5.6D EX DC Lens for Sony A is ideal for professionals and enthusiasts alike because of its Super-Wide Zoom, Lightweight Construction & Variable Aperture! Sigma 10-20mm f/4-5.6D EX DC Lens for Sony A possesses a bright f/4-5.6D variable aperture that allows crisp imagery in difficult lighting conditions. Further, it provides improved control over the depth of field that facilitates subject isolation and enables working with selective focus techniques. Additionally, the variable f/4-5.6D aperture allows consistent performance even in the full zoom range. Finally, the variable aperture is a great weight management system too. Our Take on the Sigma 10-20mm f/4-5.6D EX DC Lens for Sony A: The lens is a combination of DC and EX lenses. DC lenses make the lens compatible with DSLRs. Further, the image circle of the DC lenses is suitable for DSLR Image sensors because of their smaller dimensions. Apart from better compatibility with DSLRs, the smaller dimensions also make the lens lightweight and portable, in turn, appropriate for traveling photographers and videographers. The EX lenses are known for their superior technology. The lens design incorporates three SLD and two aspherical elements that reduce chromatic and spherical aberrations and limit distortion. Further, the rounded seven-blade diaphragm adds smoothness and results in astounding bokeh quality. Also, the Internal Focusing design renders smooth and quick autofocus along with a non-rotating filter attachment. The lens is appropriate for Sony Alpha and Minolta AF digital cameras and provides a super-wide zoom. This super-wide zoom functionality makes the lens perfect for indoors and landscape photography, which further adds to its usefulness for traveling photographers. In addition, it is well-suited for distant photography applications such as wildlife or sports matches photography. TOP 10 KEY FEATURES: Lens Construction: 13 Elements in 10 Groups Angle of View: 102.4° to 63