[share_ebook] Choosing And Using a Refracting Telescope (patrick Moore's Practical Astronomy Series)

A valuable reference that fills a number of niches including that of a buyer's guide, technical desk reference and observer's field guide. It documents the past market and its evolution, right up to the present day.

In the 1960's, American amateur astronomer, John Dobson, designed a revolutionary kind of astronomical telescope featuring a lightweight large-aperture reflecting system on a simple mounting, using the then-revolutionary material called teflon. The design combines simplicity and portability with large-aperture prowess. Thirty years later Dobsonians remain supreme for visually observing faint deep-sky objects and are one of the best-selling large telescopes in the USA and Europe. This popularity is reflected in the recent increase of companies now heavily marketing Dobsonians, in particular, Meade (the "Lightbridge" range), Orion USA (XT Intelliscope series), and Skywatcher (Skyliner and Flextube models). This book is the ultimate guide to buying and using commercial Dobsonians, both 'Econo' and 'Primo' models, with in-depth accounts for the various models (plus accessories) on the market and descriptions of the many innovations that amateurs have made to optimize their telescopes' performance.