Explore Scientific Eyepiece Review When I first bought my first telescope in the 1970, there were many types of eyepieces to choose. The designed had names like Ramsden, Erfle, Huygen, Kellner, König and Orthoscopic, to name a few. Each had pros and cons. Eye relief, exit pupils, and field of […]
When thinking about the GSO Eight Cassegrain telescope, its worthwhile to look back to Laurent Cassegrain who was a 17th century French Roman Catholic priest and is given credit for inventing the telescope design that carries his name. Cassegrain telescopes use a parabolic primary mirror with a hyperbolic secondary mirror. […]
By Dr. James R. Dire In 2017, I picked up two new William Optics telescopes: a Twentieth Anniversary Edition Fluorostar 132 (132-mm f/7 triplet Apo) and a William Optics Zenithstar 61. In a previous article, I reviewed the Fluorostar 132. Here, I will review the William Optics Zenithstar 61. The […]