The Voigtlander Ultron 40mm f/2 SL IIS Aspherical is a compact standard lens for Nikon F mount, styled after the classic Nikkor lenses of the 1970s with a distinctive ridged focus ring and metal construction. It works equally well on Nikon film SLRs and digital SLRs, with a full frame image circle and a natural 40mm field of view. The optical design uses 6 elements in 5 groups, including an aspherical element, with a 9-blade diaphragm for smooth out of focus rendering. The lens focuses down to 0.25m, closer than the earlier SL II version, without needing a supplementary close-up lens. The SL IIS is built to the Nikon Ai-S standard with an integrated CPU, so compatible Nikon cameras can meter normally and record lens data in Exif. It also includes the meter coupling prong, making it compatible with pre-Ai Nikon bodies as well. The lens weighs 260g and takes 52mm filters. Focusing is fully manual.Key Features Compact 40mm f/2 full frame standard lens 6 elements in 5 groups with an aspherical element Close focus to 0.25m without a close-up lens Nikon Ai-S design with integrated CPU for metering and Exif Meter coupling prong for pre-Ai body compatibility Classic ridged styling with 52mm filter thread Available in Nikon F mount, black finish, manual focus Why Choose A classic-styled 40mm with modern CPU integration. Equally at home on a vintage Nikon film SLR or a current full frame DSLR.