The 40 mm/1:1.2 Nokton aspherical is a fast manual lens. The lens is the world's first full-frame 40 mm lens with an F1.2 aperture while maintaining its compact size. The optical design incorporates two aspherical lens elements for reliable optical performance and soft bokeh at maximum aperture.

When used on cameras with an APS-C sensor, the focal length of 40 mm corresponds to approximately 60 mm, so the lens can be used universally as a standard lens on both full-frame and APS-C cameras.

The aperture has an adjustment in 1/3 steps. The lens is equipped with the selective aperture control system to allow continuous adjustment of the aperture for video recordings.