SkyWatcher 45 Degree 1.25" Erect Image Diagonal
Most of the telescopes work perfectly well during daytime as well as for astronomy. If you have a refractor or a Schmidt-Cassegrain telescope and you want to use it for terrestrial observations, this Sky-Watcher Erect Image Diagonal is the most useful accessory you can buy.
Normally, image created through telescopes may be either upside down, flipped so that you see a mirror image, or a combination of the two. It will be very confusing when you are trying to track a moving boat or flying bird. This problem can be corrected easily by using a erect image diagonal
Simply remove the standard diagonal from the telescope’s focuser or visual back, and install the SkyWatcher 45º Erect Image Diagonal, then when you insert an eyepiece, objects will be right side up and left-to-right correct. The 45º angle of this Amici prism diagonal is very comfortable for daytime observations, where the telescope is often in a horizontal position.
*Diagonal is not suitable for Newtonian Telescopes because they have not enough back focus.