#AGENA ASTRO PRODUCTS FREE#

Like all telescopes sold by Agena, the GSO Eight Cassegrain was evaluated physically, mechanically and optically before it was shipped. The telescope was wrapped in plastic inside form fitting Styrofoam all in a double-layered cardboard box. Image 1 shows the care taken in packaging the telescope. The telescope arrived within 5 days of placing my order.

#AGENA ASTRO PRODUCTS FREE#

The company offers fast service, free shipping, great prices, and superb customer service!

I have purchased a lot of equipment from Agena in recent years, including a Celestron mount and a whole arsenal of eyepieces. I purchased an GSO Eight Cassegrain (8-inch classical Cassegrain) from Agena Astro Products () out of Cerritos, California. In this article I will review the mid-sized 8-inch Cassegrain. Cassegrains have never been available in the amateur telescope market until very recently, when Guan Sheng Optical, out of Taiwan, starting manufacturing 6-, 8- and 10-inch classical Cassegrain telescopes. However in the latter half of the twentieth century, cheaper Schmidt-Cassegrains and much faster Ritchey–Chrétien Cassegrains replaced them. Image 1 – Agena Astro tested the 8-inch classical Cassegrain telescope before repackaging it in this doubled layer cardboard box with ample Styrofoam.Ĭassegrains were the main research telescope for more than a century. Cassegrains were lighter and easier to mount on clock drives. Secondly, the mirror design provided long focal lengths without the need for long optical tube assemblies. So astronomers no longer had to climb ladders to get to the eyepiece as was required with large Newtonians. First, the focus is behind the primary mirror. For most of the next century, the largest telescopes made were Newtonians.īy the mid-nineteenth century, Cassegrains became the preferred telescope for astronomical research for several reasons. While the first telescopes were refractors, the first reflector was made by Isaac Newton and is referred to as a Newtonian. With all these variations, the original Cassegrain design is commonly referred to as the classical Cassegrain. Variations of Cassegrain telescopes have been developed over the years with names such as Schmidt-Cassegrain, Ritchey–Chrétien Cassegrain, and Dall-Kirkham Cassegrain, to name a few. Most Cassegrains have focal ratios (f/#) between 12 and 20. The secondary mirror directs the light through a hole in the center of the primary mirror where it comes to focus. Cassegrain telescopes use a parabolic primary mirror with a hyperbolic secondary mirror. When thinking about the GSO Eight Cassegrain telescope, its worthwhile to look back to Laurent Cassegrain who was a 17 th century French Roman Catholic priest and is given credit for inventing the telescope design that carries his name.

Agena astro products