Celestron Erect Image Prism 45

Celestron Erect Image Prism 45°

Converts a refractor or catadioptric telescope to be suitable for viewing terrestrial objects during the day. When viewed through a telescope with a regular mirror or star-angle prism, objects are either upside down, mirror images, or both. This is fine for stargazing, but it is difficult to follow terrestrial objects.

By installing the Celestron 45º turning prism in the telescope's focusing tube instead of a standard angle mirror, and placing the eyepiece on the turning prism, objects will be turned correctly along both axes.

Note: Installing a rotating prism on a Newtonian telescope does not correct the angle of the image to normal. The optical design of a Newtonian telescope always produces an image that is oblique in the direction of rotation.