Celestron Image Erecting Prism 1.25" 94112-A

Celestron Image Erecting Prism Review

The Celestron Image Erecting Prism is used on refracting telescopes to correct the image.  Refracting telescopes reverse what you're seeing in the night sky and turn it upside down.  This image erecting prism will correct that, making images appear as they would to the naked eye.  This image erecting prism is built at a 45 degree angle and will work on any telescope that utilizes 1.25" eyepieces.

What is an image erecting prism?

An image erecting prism helps to correct a common problem with telescopes.  Because of the way most telescopes are designed, images seen through the eyepiece are sometimes reversed.  This is completely normal for most catadioptric and refracting telescopes, because of the combination of mirrors and lenses used to magnify the object you see in the sky.  An unfortunate side effect of this lens and mirror combination is that it can be difficult for some amateur astronomers to track objects using declination and right ascesnion, because the reversed image is not what the human eye is used to.  An image erecting prism solves this common problem by passing light through a prism that corrects a reversed view, allowing astronomers to track objects through intiutive adjustments to declination and right ascension.  

In addition to correcting for inversion, the image erecting prism also provides a more comfortable view.  The usual 90 degree mirror supplied with most refracting telescopes can somtimes be uncomfortable, and a 45 degree prism often helps with the discomfort and disorientation that results from using stock mirrors.