Lens construction: 6 elements 5 groups, aperture range of f1.7 - f22 | Lens Not Attached:MANUAL LENS need you to enable"M mode" or "Release without lens" in the setting of camera.Minimum focusing distance: 0.5 | The lens is a fully manual lens, all metallic construction, well-built, light weight and compact | Great build quality with all metallic construction, making the lens solid, waterproof and dustproof | USE shooting for portrait, action, nighttime, landscape, architecture, street, astronomy, interior, wedding etc