The Sony SAL-135F18Z 135mm f/1.8 Carl Zeiss Sonnar T* AF Lens from Sony is a bright Alpha lens with a maximum aperture of f/1.8. This wide maximum aperture provides very shallow depth of field, as well as smooth blurred bokeh background effects in your images. Its 135mm focal length is the 35mm equivalent of a longer 202.5mm telephoto lens when used on cropped APS-C sensor cameras. It is constructed of 11 elements in 8 groups, as well as two Extra-low Dispersion (ED) glass elements, which all help to deliver sharp, clear photos. It has a minimum focusing distance of 2.4' and a front-end filter diameter of 77mm.