Samyang SY300M-N 300mm F6.3 Mirror Lens for Nikon DX Cameras Includes a Focal Length Matched Lens Hood That's Reversible for Storage Focuses to 2.9ft (0.9m) and Accepts 58mm (Front) or 25.5mm (Rear) Filters Optical construction of 8 lenses in 8 groups provides exceptional image quality Ultra Multi Coating (UMC) For Increased Light Transmission and Reduced Internal Reflections Catadioptric (Mirror) Design Provides 450mm (35mm Equivalent) of Power in a Super Compact Size and Shape