The AF 135mm f/1.8 FE from Samyang is a medium-length telephoto prime designed for full-frame Sony E-mount mirrorless cameras. Offering outstanding resolution, the optical design incorporates three extra-low dispersion elements and an ultra-precision aspherical element, which suppresses both chromatic and spherical aberrations for improved sharpness, color accuracy, and clarity. The lens has a linear STM autofocus motor for quick, quiet, and precise focusing performance, plus a minimum focusing distance of just 2.3" to suit working with close-up subjects. Three different customized buttons for enhanced functionality include a focus hold button, a custom switch, and a focus range limiter switch. Medium-length telephoto prime designed for full-frame Sony E-mount mirrorless cameras, however can also be used with APS-C models where it provides a 202.5mm equivalent focal length. Bright f/1.8 maximum aperture benefits working in low-light conditions and also affords significant control over depth of field for working with selective focus techniques. An ultra multicoating has also been applied to reduce ghosting and flare in order to achieve higher contrast when working in strong lighting conditions. Focus hold button lets you keep the lens locked to your desired focusing distance. Also allows you to assign functions such as Eye AF in settings on the camera body. Focus limiter switch lets you constrain the focusing to two different ranges to suit different applications: 27 to 79" for closeup shooting or 59" to infinity for standard shooting. Eleven-blade diaphragm contributes to a pleasing out-of-focus quality that benefits the use of shallow depth of field and selective focus techniques. It also features an astro-focus function for astrophotography. The weather-sealed construction offers protection against dust, light rain, and snow.