Discover this rare Vintage Bell & Howell Type I 6 f/2.5 Aerial Lens for large format photography enthusiasts. Manufactured in the 1940s, this iconic screw mount lens offers exceptional optical performance with an effective focal length (EFL) of 154mm. Ideal for collectors and photographers seeking authentic aerial optics from WWII-era technology. Cosmetic Grade: C4-Used Good - Features moderate wear consistent with age, including some scratches and patina on the aluminum exterior, but remains in solid, attractive condition. Functional Grade: F4-Hardware Functional - Fully tested; lens mounts securely, focuses smoothly in auto and manual modes, and delivers sharp images with its bright f/2.5 maximum aperture. Focal Length: 100-220mm (optimized at 154mm EFL). Type: Standard prime lens for aerial and large format use. Focus Type: Auto & Manual. Maximum Aperture: f/2.5-4.4 for versatile low-light shooting.