
Observatory-class opticsCelestron's 20-inch f/6.8 field-corrected modified Dall-Kirkham telescope is for the professional. It features stellar-quality optics topped off with a newly designed massive observatory-class computerized German equatorial mount. Revolutionary Optical SystemCelestron's Dall-Kirkham telescope is near optical perfection exceeding off-axis performance of even the Ritchey-Chretien design. RMS spot sizes at the edge of a 35mm frame remain smaller than a single pixel on the most advanced CCD cameras available to amateurs today. You'll get star points not blurs or cones across the full field of view. The optical system also features a conical primary mirror with low thermal mass and three cooling fans to minimize the cool-down time. Celestron's no-compromise design provides the superb resolving power for which Dall- Kirkham telescopes are known but without the coma that has previously limited their wide-field performance. XLT coatingsCelestron's XLT coating process uses state-of-the-art thin-film vacuum-deposition technology. To ensure consistent optical coatings of the highest quality the process is tightly monitored and controlled by highly trained technicians. Prior to coating each optical element is thoroughly cleaned and inspected to ensure proper adhesion of the films. Materials used in our reflective and anti-reflective coatings including aluminum hafnium oxide titanium dioxide silicon dioxide and magnesium fluoride are the purest available exceeding 99.99 percent. The result is image clarity so stunning it must be seen to be believed. Astrograph mountThe C20 comes with a professional-class pier. The pier includes fully integrated electronics as well as Celestron's renowned and proven NexStar? software. Tracking accuracy is better than 5 arc seconds peak to valley without enabling the PEC function. The C20 is the most sophisticated telescope Celestron has ever designed and manufactured. The C20 is a system that meets the highest standards Celestron sets for technical innovation design and engineering superiority precision performance and uncompromising optical quality. And it'll provide superb performance for a lifetime-plus.Shoot the planets with the Celestron NexImage Solar System Imager