The Williams Optics Gran Turismo 81 WIFD is a three-element apochromatic refractor, with lenses using FPL-53 glass. This telescope produces images with unsurpassed aberration correction.

William Optics Internal Focus Design

The Gran Turismo 81 WIFD is the first of the GT series to include the William Optics Internal Focus Design (WIFD) system. This innovative and revolutionary design combines a precision (patented) internal focusing mechanism with the highest quality optics available, providing the ultimate Apochromatic refractor for astrophotography.

Designed from the ground up with the ability to handle the newest generation of large, heavy, high-resolution cooled cameras, the rock-solid optical tube assembly is uncompromised in quality. The movement of the focuser is integrated inside the main tube assembly, so there are no movements of a focuser drawtube visible from the outside.

More importantly, the weight of the imaging train (camera, filter wheel, off-axis guider, rotator, etc.) is not borne by the focuser drawtube. This eliminates problems of flop and collimation, ensuring excellent imagery.

The user can enjoy the benefits of a traditional two speed fine focuser, while not worrying about limitations typically found in traditional rear mounted focusers.