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 aberation 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 and holds almost 50% more weight. 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. It is easy to use and functions well for both the visual observer and astrophotography. Motion is controlled by included control knobs for accurate slewing. The polar altitude adjustment varies from 0° to 62° in altitude. Add the DD3 Motor Set for accurate tracking.Optional single axis or dual axis motors and controllers are available as are a polar alignment telescope with setting circles. |