The 45mm focal length provides a natural appearance, approximating how we perceive a scene with our own eyes. It is actually closer to the human eye than a 50mm focal length is. This focal length is great for general purpose use and can be readily used for portraiture, extreme sports, parties, lifestyle, architecture, landscape, street photography and more. Optically, the lens is made up of 7 elements in 6 groups. Two Aspherical plus one Extra-low Dispersion element and Ultra Multi-Coating are utilized to effectively control vignetting, distortion and chromatic aberration. Additionally, the rounded nine-blade diaphragm and F1.8 bright aperture produce a pleasing out-of-focus quality when working with shallow depth of field techniques. The minimum focusing distance is 17.7” and the 49mm non-rotating filter mount allows for easy use of polarizing and other filters that require precise positioning. For Sony APS-C sensor cameras, the focal length is equivalent to a moderate telephoto of 67.5mm. Construction has been optimized for portability, compactness, ergonomic handling, and the durability of a metal barrel. Offering quiet and accurate autofocusing with enhanced speed and at 5.71oz in weight and 2.43” in length, it is the perfect lens to live on your Sony camera always. Don’t miss that special and unique moment! It is often said “The best camera (and lens) is the one you have with you”.