KENKO Telephoto Lens Mirror Lens 400mm F8 NIIS Pentax K Mount Reflective Optical System Manual Focus Mount Replaceable Full Size Compatible Black

[Super telephoto in a small body] A mirror lens that uses a reflective optical system to achieve a small and lightweight super telephoto of 400mm. [Characteristic "ring bokeh"] The bokeh area becomes a "ring bokeh" that looks like there is a hole in the center, creating a fantastic depiction. [Easily replaceable with mounts from other companies] By replacing the T-mount adapter, you can easily change the mount. [Uses a new T-mount adapter] Uses a new and improved T-mount adapter. It is designed with consideration given to reducing internal reflections. [Product specifications] Focal length: 400mm / Brightness: F8 (fixed) / Lens composition: 6 elements in 2 groups / Angle of view: 6° 8' (35mm format equivalent) / Filter diameter: 67mm (front), 30.5mm (mount) side)/Minimum shooting distance: Approx. 1.15m/Maximum shooting magnification: 1: 2.5/Focus method: Manual focus (front lens extension method)/Size: 112 x Φ74mm (mirrorless mount), 82 x Φ74mm (SLR mount)/Weight: 545g (mirrorless mount), 500g (SLR mount)