William Optics 90° 1.25″ Zenith prism Cat 51 WIFD

William Optics 90° 1.25″ Zenitprisma Cat 51 WIFD: comfortable and upright viewing with your Cat 51 WIFD

This William Optics zenith prism is the visual complement to the Cat 51 WIFD. It bends the light 90 degrees, allowing you to look comfortably into the eyepiece from above, and it presents the image upright: you'll see birds, landscapes, and the moon exactly as they appear outdoors.

The BaK-4 prism has a dielectric coating that keeps light transmission high and reflections low. The included 2 to 1.25 inch adapter and ring clamp firmly and scratch-free mount the prism onto the WIFD focuser.

Why an erecting prism on an astrograph

The Cat 51 was built as an astrograph, but with this prism and an eyepiece, you have a compact spotting scope and travel binoculars. Two instruments in one case.

Featured accessories

Combine with a 1.25-inch low-power eyepiece for the maximum field of view.

For whom yes and for whom no

• ✓ Cat 51 WIFD owners who also want to view visually and during the day
• ✗ RedCat 51 owners: choose the version with an M56 adapter

Specifications

You can find more accessories for this brand at the William Optics brand page.