Alstar 1.25 inch 90-Degree Erecting Prism Optical Prism Inside Rather Than a Mirror which Makes Your Image Clear and Sharp with 1.25 inch Eyepiece Adapter and Brass Rings for Astronomical Telescope

Alstar 1.25 inch 90-Degree Erecting Prism Optical Prism Inside Rather Than a Mirror which Makes Your Image Clear and Sharp with 1.25 inch Eyepiece Adapter and Brass Rings for Astronomical Telescope

• With this 90-degree erecting prism transform your telescope into a telescope for nature observation with upright and left-right corrected image
• This is a great diagonal for daytime terrestrial use and night time astronomy applications for telescopes or spotting scopes;filter thread for any 1.25 inch filter and accepts standard 1.25 inch eyepieces
• The Erecting Prism comes with dust cap and dust plug which prevent dust from entering, for long-time use
• Constructed from genuine optically processed BK7 glass; this product features a high-quality optical prism instead of a mirror ensuring clear and sharp image quality
• The prism housing is made of ABS plastic and the barrels are metal for a secure fit; A clamping aluminum screw secures the eyepiece; This allows sideways viewing without the eyepiece falling out

1.25" 90-degree diagonal features an image erecting prism that allows you to look into a telescope at a 90 degree angle. It produces an image that is oriented properly, which means that the image is upright and correct from left to right (i.e., a correct, non-inverted, non-reversed image).This is a great diagonal for daytime terrestrial use with small telescopes or spotting scopes. It can also be used for astronomy applications, especially when you would like to match the orientation of the star field with "correct" star maps and charts. The prism housing is made of precision molded ABS plastic and the two end barrels are precision machined from aluminum. The 1.25" nosepiece is threaded to accept standard 1.25" astronomy filters. Please Note: This diagonal can only be used with refractor telescopes and some catadioptric telescopes like Schmidt-Cassegrain, Maksutov-Cassegrain, etc. It not meant for use with Newtonian / Dobsonian reflector telescopes or other variants of Newtonian telescopes.