Compact, Lightweight Fixed 50mm Focal Length Lens. Large F/1.8 Aperture for Low-Light Photography and Creative Background Blur. A Stepping Motor (Gear-Type STM) Provides Smooth and Quiet Continuous AF During Video Recording, As Well As When Shooting Photos. Control Ring for Direct Setting Changes. Optimized Lens Placement and Coatings Help Deliver Outstanding Color Balance, While Minimizing Ghosting and Flare. Circular 7-Blade Aperture Helps Deliver Beautiful, Soft Backgrounds.