GSO Elliptical Secondary Mirror - 28mm
For years, GSO has made dobsonian telescopes sold under various labels. Users of these scopes know the excellent quality of the optics included, and they have a well-deserved reputation for being the finest mirrors in their price range. We are now pleased to offer virtually the entire line of GSO's Newtonian optics in the US market.
GSO's elliptical flat mirrors have the same high quality as their parabolic primary mirrors. Made from optical grade BK-7 glass, all mirrors have a reflective aluminum coating with a reflectivity of approximately 92-93%. The aluminum coating is protected by a silicon oxide (SiO2) over-coating.
GSO uses high-volume, state-of-the-art, high quality manufacturing and test lines. GSO guarantees diffraction limited performance, but their secondary mirrors typically have a mirror surface quality of 1/12 wave RMS at least, and often better. This very smooth mirror surface results in excellent optical performance with practically no light scatter.
Besides elliptical secondary flats, we also offer matching GSO parabolic primary mirrors, mirror cells, and spiders (all sold separately).