The 45° Erecting Prism is a clever little device which serves two purposes for me.
- It allows a more comfortable viewing angle for visual observations
- It corrects the orientation of the sky.
I was always having problems with the reversed view you get, and often getting lost by moving in the wrong direction!
Astronomy telescopes show an upside down reversed images. This is normally fine for astronomy but can be a little confusing for the novice. Erecting Prisms correctly orientate the image and the 45Â° prism makes the viewing angle a lot more comfortable.
Erecting Prism and Terrestrial Observation
Erecting Prisms are also good for using your astronomical telescope for more terrestrial viewing. This is because they will correctly orientate the image of the birds in the eyepiece.