Accurate Scales: Manual focus design is complemented by depth of field and distance scales, which facilitate the use of pre focus technology to provide pointed, clear images. Photography Essentials: The 500mm F6.3 ultra long zoom lens is a great choice for bird and wildlife photography as well as ultra long distance shots. Lens Type: A achromatic refractor mirror design is used to obtain images with good peak contrast and flare control. You can use this lens in M manual exposure mode. Optical Design: 4 group, 4 piece optical structure with multi layer MC coating suppresses lens spotting and ghosting, improving contrast and color fidelity. Exquisite Craftsmanship: The lens can be used with the included T2‑M4/3 adapter . High strength alloy body and optical glass, strong texture and beautiful appearance.