Equipment

Telescopes, binoculars, and accessories for amateur astronomy.

The Five Numbers That Explain a Telescope

April 4, 2020 by Brian Ventrudo Filed Under: Astronomy Equipment

A 14" Schmidt-Cassegrain telescope (credit: Celestron). — A 14″ Schmidt-Cassegrain telescope (credit: Celestron).

Before we launch into the pros and cons of the types of telescopes available to stargazers today, let’s have a quick look at 5 key numbers that describe the operation and performance of every telescope, from the junk scopes in a department store to the venerable Hubble Space Telescope. Once you understand these 5 numbers, you will understand the similarities and differences between telescopes, and you will know how to choose the best scope for your own interests and budget [Read more…] about The Five Numbers That Explain a Telescope

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The Purpose of a Telescope

April 2, 2020 by Brian Ventrudo Filed Under: Astronomy Equipment

The 8.2-m primary mirror of Yepun, Unit Telescope 4 of ESO's Very Large Telescope, after its recoating in early March — The 8.2-m primary mirror of Yepun, Unit Telescope 4 of ESO’s Very Large Telescope, after its recoating in early March

Here we cover an essential but often overlooked point about telescopes. It may seem strange to cover this, but once you understand this point, you’ll understand the trade-offs involved in choosing a good telescope for stargazing. The fact is, most beginners believe the purpose of a telescope is to magnify objects, to make them appear bigger. This is not true. What, then, is the purpose of a telescope? [Read more…] about The Purpose of a Telescope

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The Basics of Electronically-Assisted Astronomy

July 27, 2018 by Brian Ventrudo Filed Under: Astronomy Equipment

The Lagoon Nebula (M8) images with a Mallincam Extreme video camera with a Meade 8” LX10, focal reducer, and light-pollution filter. Credit: Jim Thompson.

Electronically-assisted astronomy (EAA) is a relatively new and often misunderstood pastime, one that lies somewhere in the continuum between strictly visual observing and hard-core astrophotography. Simply put, EAA allows you to see what would otherwise not be possible to see using an eyepiece alone. It’s an ideal way to complement purely visual observing, and it’s perfect for stargazers who don’t have the visual acuity or patience to look through an eyepiece [Read more…] about The Basics of Electronically-Assisted Astronomy

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Vixen’s Astonishing SG 2.1×42 Wide-Field Binoculars

August 19, 2016 by Brian Ventrudo Filed Under: Astronomy Equipment

Vixen Optics SG 2.1x42 binoculars (credit: Vixen) — Vixen Optics SG 2.1×42 binoculars (credit: Vixen)

While Galileo’s profound discoveries with his first telescope in 1609 are rightly celebrated in the annals of science, the optical design of his first telescope is not. Based on a simple convex objective lens and a concave eyepiece, Galileo’s early telescopes gave drinking-straw-narrow fields of view and and image brightness that dropped off drastically at the edge. His design was quickly replaced by the so-called Keplerian telescope which we all use today. So imagine my surprise when I discovered a relatively new set of binoculars from Vixen Optics that are based on a modern version of Galileo’s original telescope design. These Vixen SG 2.1×42 binoculars, which magnify just 2.1 times and have objective lenses 42 mm diameter, give extraordinary wide-field views of entire constellations, and some say that observing with these binoculars is like having ‘super vision’ [Read more…] about Vixen’s Astonishing SG 2.1×42 Wide-Field Binoculars

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Finder Scopes

July 12, 2016 by Brian Ventrudo Filed Under: Astronomy Equipment, Astronomy for Beginners

A magnifying finder scope mounted to a telescope.

When you look through a telescope, you look at a very small slice of sky. That makes it almost impossible to point your telescope directly at your target. Sometimes, it’s even hard to find the Moon directly with the main tube of a telescope, even at lowest magnification. That’s why most telescopes come with a finder, a small telescope or range finder to help you easily locate objects in the night sky. There are two main types of finders: magnifying finders and non-magnifying finders [Read more…] about Finder Scopes

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