The Helios 44M-4 lens is a standard lens for single-lens reflex cameras and is suitable for all types of photography, including portraits and landscapes. This lens is designed and manufactured at the Krasnogorsk machine plant. Helios 44m-4 is a manual diaphragm with 6 blades. It can be attached to modern cameras using a mount adapter. Specifications Aperture / focal length: 2/58 Diaphragm scale: 2-16. Focus range: 0.55m-10m, infinite. Viewing angle: 40. Lens / Part Quantity: 6/4. Lighting efficiency: 0.80. Resolving capacity (line 1mm). Center / edge: 38/19. Filter mount: M52 x 0.75. Weight: 0.3kg. Aperture / focal length: 2/58. Diaphragm scale: 2-16. Lens / component quantity: 6/4. Light efficiency: 0.80.