The NA140S (Neo-Achromatic) refractor features a two element secondary lens at the rear of the optical tube to provide a flatter field of view (Petzval design). Spherical abberation and field curvature are less than 1/3 to 1/5 of standard doublet refractors.
The GPD2 equatorial mount is the stronger and heftier of the GP mounts. With it’s solid steel R. A. and Declination axes and brass worm gears this mount will hold up to years of heavy use. In order to assure accurate tracking for astrophotography the worm, gears are especially machined to a very high precision that minimizes periodic error. Add the DD2 Motor Set for accurate tracking.
The NA140S (Neo-Achromatic) refractor features a two element secondary lens at the rear of the optical tube to provide a flatter field of view (Petzval design). Spherical abberation and field curvature are less than 1/3 to 1/5 of standard doublet refractors.
The GPD2 equatorial mount is the stronger and heftier of the GP mounts. With itï¾’s solid steel R. A. and Declination axes and brass worm gears this mount will hold up to years of heavy use. In order to assure accurate tracking for astrophotography the worm, gears are especially machined to a very high precision that minimizes periodic error. Add the DD2 Motor Set for accurate tracking.
