ZWO OAG-L with 12*12 Prism & 1.25" Holder - OAG-L type-binocular-accessories 20") Diopter Adjustment Range: ±4

20") Diopter Adjustment Range: ±4 Twilight Factor 40 Relative Brightness: 16 Limiting Stellar Magnitude: Ideal: 12

This Sky Mentor Image Rectifier Universal Erecting Prism is a new roof design for Newtonian Reflector Telescopes

4 lbs) make it perfect for field use and travel

and the lighter faculae that look like someone spilled a bit of milk across the surface

10X–200X MAGNIFICATION WITH PROFESSIONAL-QUALITY OPTICS: 5-element IR-cut glass lens and 3

ZWO OAG-L with 12*12 Prism & 1.25" Holder - OAG-L type-binocular-accessories 20") Diopter Adjustment Range: ±4An OAG, or off axis guider, offers a better way to guide when used with longer focal length telescopes when compared to traditional guide scopes, which can add unwanted weight, balance and possible flexure issues. An OAG also lets you guide at the same focal length as your telescope. This is especially important to focal lengths beyond 1000mm. The ZWO OAG L Off Axis Guider has a large prism size of 12*12mm, far bigger than standard ZWO OAG's prism