The manual focus Samyang 20mm T1.9 VDSLR ED AS IF UMC Lens features a bright T1.9 aperture, 0.2m minimum focus distance, & 13 elements in 12 groups. Designed for use with Micro Four Thirds fit cameras, this cine lens has 2 aspherical & 3 extra-low dispersion lenses to prevent aberrations & light dispersion, & is optimally designed for professional follow focus systems.