Gran Turismo 81 APO with Internal Focus Design

The William Optics Gran Turismo 81 is an 81mm f/5.9 triplet apochromatic refractor with a 478mm focal length, featuring a precision internal focusing mechanism combined with the highest quality optics available, providing the ultimate Apochromatic refractor. The patented WO center focuser uses precise internal sliding of fixed optics to prevent image shift, with smooth rack and pinion design incorporated into the focuser to provide super fine adjustability for critical focus. Built with FPL-53 apochromatic glass, it produces crisp, clean, high contrast, and sharp images without chromatic aberration, making it an excellent choice for demanding astrophotography projects with heavy imaging systems.