Homemade 90 Degree Erecting Prism Diagonal for DIY Telescope
Keeps your knees clean! View in comfort from a 90 angle Image is right side up
Observing through your astronomical telescope can be awkward due to the angle of the eyepiece once the telescope is set up. A star diagonal alters the angle of the eyepiece to make observing more comfortable. The majority of telescopes will show an upside down or reversed image to correct this you require an erecting prism.
and i do it with aluminium alloy, Erecting Prism Diagonal take from old microscope