The ShortTube 80: A Tribute to a Modern Classic Refractor.

The ShortTube 80 Telescope:  A User’s Guide.

We live in a time of unprecedented technological progress, where nearly every aspect of our lives has been transformed by scientific breakthroughs. This is no less so in amateur astronomy, where an enormous variety of good telescopes are now available to the consumer to suit nearly everyone’s budget. And while, amateur astronomers have never had it so good, it is also true that choosing a telescope has become a daunting task, where rivalling telescope companies jockey for power to get their products into the hands of users.  And yet despite this golden age for buying and using telescopes for astronomy and nature studies a few instruments stand out, having stood the test of time and which continue to be used with affection despite there being better models on the market.

I speak of course of the venerable ShortTube 80, a simple 80mm achromatic doublet with a focal length of 400mm.  Ever since it was first conceived of back in the early 1990s, its light weight, low cost and ultra-portability have endeared it to a great many amateur astronomers over the years, where it has flourished as a visual telescope, an imaging system and as a hard-working guiding ‘scope for many astrophotographers. With reports from owners of this telescope began to circulate, more and more ShortTube 80s found their way into amateur hands, where it quickly became one of the best-selling telescopes of all time.

The SkyWatcher incarnation of the ShortTube 80 refractor; the Star Travel 80.

In this book, we’ll be taking a long, hard look at the ShortTube 80, as a visual and imaging telescope. Its great popularity was in part attributed to a gamble taken by the founding president of Orion Telescopes & Binoculars, Tom Geisler, who’s keen business acumen spotted the potential of a small, inexpensive rich field refractor that could be taken anywhere at a moment’s notice. Soon the adverts appeared on the pages of Sky & Telescope magazine and the orders started to pour in. The iconic model, the white tubed Orion ShortTube 80, quickly became a huge hit with birders and amateur astronomers, where it served as an excellent rich field telescope for deep sky viewing. But soon, more curious reports began to surface in books or on online amateur astronomy forums, where amateur astronomers reported some interesting results on the traditional high-resolution targets like the Moon, Sun, planets and double stars.

A trip down memory lane: one of the original glossy adverts of the Orion ShortTube 80 as it appeared in Sky & Telescope magazine in the 1990s. Image credit: Orion Telescopes and Binoculars(used with permission).

 

In this volume, I’ve distilled down my own experiences with the venerable ShortTube 80, where I describe the many deep sky targets accessible to most anyone using this telescope, presenting a voluminous list of targets and notes on how best to see them. Conventional wisdom says that the ShortTube 80 is not a good ‘scope for looking at high magnification targets like the Moon, planets and double stars. And while there is certainly some truth in these claims, my own findings are far better than what many have claimed in the past. The truth is that this ubiquitous 80mm f/5 refractor can indeed provide decent images at high magnification by using good eyepieces, color filters and the like. Indeed, I’ll be discussing how amateurs can soup up their ShortTube 80s to push the envelope on these difficult targets. Indeed, my own field work shows that the same telescope will resolve binary stars down to near the limit of its theoretical resolving power of about 1.5”. What is more, I have enjoyed some good images of Jupiter, Saturn and Mars with the same telescope and I show the reader how to maximise the telescope’s potential on these targets.

An untrained telescopic eye sees little, but a trained eye reveals good details. Sketch of Jupiter with GRS as seen through the ShortTube 80 at 100x on the evening of May 19 2018 using a Baader 495 yellow longpass filter, time 23:40 UT

Astro-photographers even tried their hands at creating good quality astro-images with the ShortTube 80 with surprising results. When coupled to a narrow band etalon filter, the same telescope can yield magnificent images of the Sun, with its various filaments, prominences and sunspots. In the hands of deep sky imagers, the ShortTube 80 has also proven to be a capable instrument. Bright stars do throw up prominent purple halos from the inherent chromatic aberration of this fast achromatic refractor but with some clever image processing, have managed to create impressive images of familiar deep sky objects such as the Pleiades and the Orion Nebula. Others have successfully coupled narrow band filters to the ShortTube 80 to capture spectacular images of elusive nebula strewn across the sky.

The Orion Nebula and hinterland as imaged by the ShortTube 80. Image used with permission.

So, if you’ve got an old ShortTube 80 handy, give it a dust down and feed it some light. It is my fondest hope that you will find this book useful and that you will gain a greater appreciation of the true versatility of this now classic telescope.

Book Content

Introduction & Acknowledgements

Chapter 1: Under a Dark Sky…………………………………………………………………………………1

Chapter 2: The Anatomy of the ShortTube 80………………………………………………………13

Chapter 3: Mounting the ShortTube 80………………………………………………………………27

Chapter 4: Exploring the Deep Sky…………………………………………………………………….45

Observing Variable stars: 55

Novae: 58

The Celestial Sphere: 59

When and Where to Observe: 61

Atmospheric Seeing: 62

Making Sketches: 63

Favorite Seasonal Targets for the ShortTube 80:65

How About a Messier Marathon?: 110

A Modern ShortTube 80: The Meade Adventurescope 80. Image credit: Maya Doka(used with permission).

Chapter 5: Improving the High-Power Performance of the ShortTube 80…………..113

Eyepieces: 113

Color Filters: 116

Introducing the concept of ‘oligochromatic’ Strehl.

Reducing Stray Light: 121

Collimation: 123

Chapter 6: Watching the Sun……………………………….125

Chapter 7: Exploring the Moon and the Planets………………………………………………..135

Observing the Moon: 135

Lunar Occultations: 144

Jupiter Watching: 145

Observing Saturn: 148

Observing Mars, the Red Planet: 150

Observing Venus: 151

Observing Mercury: 152

Chapter 8: Exploring the Realm of the Double Stars……………………..155

Double Star Resolution Tests with your ShortTube 80:158

Some Easy Double and Multiple Stars for the ShortTube 80: 160

More Difficult Pairs Accessible to the ShortTube 80: 175

Chapter 9: The Meade ETX 80………………………………………………………183

Chapter 10: Imaging with the ShortTube 80……………………………………….191

Digiscoping: 193

Using the ShortTube 80 as Guide ‘Scope for Astrophotography: 197

Using the ShortTube 80 as an Astroimaging ‘Scope: 199

The first “premium” quality ShortTube 80 by Vixen; the A80SS WT (with a two -inch focuser).

Chapter 11: Souping Up the ShortTube 80………………………………..203

Binoviewing with the ShortTube 80: 216

Chapter 12: Founding Days: A Look at How the ShortTube 80 came to be and how it diversified over the years………………………………………………………………………………221

Chapter 13: Afterword: The Little ‘Scope That Could……………………………………….237

Index: 241

The author’s ShortTube 80 with assorted eyepieces and filters.

 

Available wherever books are sold from November 2019

 

Thanks for reading!

 

De Fideli.

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