Pairing speed and stellar optics, the Leica Summilux-M 90mm f/1.5 ASPH. is a fast portrait-length lens offering impressive subject separation using an especially shallow depth of field. The bright f/1.5 design is ideal for portraiture but also suits working in low-light conditions. Beyond the fast design, this 90mm f/1.5 is also distinguished by its advanced optical composition that incorporates a pair of aspherical elements to ensure high sharpness and low dispersion, and a floating element system is also employed to maintain consistent image quality throughout the focusing range from 3.3' to infinity. Additionally, this lens has an 11-blade diaphragm to produce an especially pleasing, rounded bokeh quality and a built-in lens hood helps to prevent lens flare and ghosting. Impressively fast f/1.5 maximum aperture affords notable control over depth of field for selective focus shooting, and also benefits working handheld in low-light conditions. Short-telephoto 90mm focal length offers a flattering image quality that is well-suited to portraiture and mid-length images, especially when used in conjunction with the shallow depth of field afforded by the bright maximum aperture. Two large-diameter aspherical elements are used to control spherical aberrations for improved sharpness and reduced distortion. A floating element system is employed to maintain consistent image quality throughout the focusing range, even at the minimum focusing distance of 3.3'. An 11-blade diaphragm produces a rounded and pleasing bokeh quality. Built-in extendable lens hood shades and protects the front element to reduce lens flare and ghosting. Additionally, the front of the lens is threaded to accept 67mm screw-in filters.