Optical tube
The Celestron 9.25-inch tube houses a 235/2350 Schmidt-Cassegrain optic. This size has earned a special distinction among SC telescopes: the main mirror has an aperture of f2.35 instead of the f1.9 used in other versions, which gives a better corrected field of view, and Celestron's engineers have also paid special attention to the optical machining.
The telescopes feature the company's proprietary StarBright XLT coating, which increases the light-harvesting capability of the telescopes. When used, the transmittance of the corrective lens reaches 98%, while the reflectance of the main and secondary mirrors reaches 95%. In addition, the contrast of the image is increased. The basic package includes a zenith prism, a 6x30 finder scope and a 25 mm Plössl eyepiece with a magnification of 94x.
The optics of Celestron tubes are hand-figured and hand-matched, which means they consistently outperform the optical quality of competing SC tubes, according to independent tests.
The tube is fitted with a 76 mm wide Losmandy rail.
