Review: Vixen SG 2.1×42 Widefield Binoculars

A 25º field of view makes the Vixen SG 2.1×42 perfect for scanning the Milky Way. Credit: Jamie Carter

Plus: Wide field of view; extends limiting magnitude; steady image; pocket-sized

Minus: Lens caps are easy to lose; image quality blurs at the edges

Small, lightweight and offering a bright image across around 25º of the night sky, the Vixen Optics SG 2.1×42 pocket-sized widefield binoculars offer something different for stargazing at constellations and the Milky Way.  

Are you an amateur astronomer? Or a stargazer? Yearning for better, clearer and sharper images of ever-deeper sights in the night sky might be the goal of a lot of amateur astronomers, but there’s a lot to be said for wide-field astronomy. Usually that means using binoculars, with casual binocular astronomers favoring 10×50 binoculars – that’s 10x magnification and a 50mm objective lens – though 20×80 are usually more popular with serious users merely for the extra magnification. 

So why would anyone want a pair of binoculars with a paltry 2.1x magnification? The Vixen SG 2.1×42 bridges the gap somewhere between naked-eye stargazing and binocular astronomy. They’re sold as “constellation” binoculars, and that’s about right. With 42mm diameter objective lenses and a vast field of view of over 25 degrees, they allow the user to scan a vast area of the night sky and extend their view into the cosmos.

The Vixen binoculars ship with a padded case, neck strap and lens caps. Credit: Jamie Carter

How much the binoculars extend the limiting magnitude for naked-eye visibility of the faintest stars depends on how dark the observing conditions are, but the Vixen SG 2.1×42 gives a gain of around +1.5. In that sense, they’re as handy for beginner stargazers trying to learn the constellations in light-polluted urban skies, as they are to more experienced observers using the binoculars in dark sky destinations. Their 25 degree field of view means the viewer can isolate and more easily study large constellations and asterisms such as the Big Dipper, Hercules and the Summer Triangle. 

Made with Miyauchi in Japan, at first glance the SG 2.1×42 look like opera glasses. In fact, the binoculars use the same Galilean system. Each lens has to be adjusted separately to achieve infinity focus, while the eye relief is such that they can’t be used to their full extent while wearing glasses. 

The Vixen SG 2.1×42 proves excellent for scanning the night sky, looking for constellations, and for generally retaining a wide-eyed view of the cosmos. In many ways they’re best categorized as being a slight upgrade on human vision, though the image quality at the periphery of the objective lens does mean significant blur at the edges of the field of view. The way to cope with that is to look only in the center of the image, and instead of moving your eyes, move the binoculars. 

If you’re headed out to dark skies, portability is everything. The Vixen SG 2.1×42’s small size makes them easy to travel with, though don’t think of them as a lightweight option; at 14.5 oz (410 grams) they’re reassuringly weighty for their size. However, they ship with a simple yet effective case that has both a belt loop and fixing for a neck strap, as well as a neck strap attached to the binoculars. Sadly, the lens caps – all four of them – and not attached, and are thus easy to lose. 

Although the binoculars are aimed at persuading dedicated naked-eye astronomers to upgrade their own built-in optics, the Vixen SG 2.1×42 will delight anyone after a little more celestial context than a 12-inch Dobsonian can offer. They’re also perfect for astrophotographers who, having set going a long exposure shot or a time-lapse sequence, may have time on their hands to immerse themselves in the Milky Way. 

What the Vixen SG 2.1×42 truly excels with is the Milky Way. If you’re lucky enough to have regular access to a night sky dark and transparent enough to show off our own galaxy in all of its glory, then the Vixen SG 2.1×42 is an incredible tool for scanning the galaxy’s billions of stars, clusters and nebulae, all while retaining a sense of the Milky Way’s enormity.

About Jamie Carter

A science, travel and technology journalist for over 20 years, UK-based Jamie Carter writes for Forbes Science, Sky and Telescope magazine, the BBC's Sky At Night, Travel+Leisure and the South China Morning Post. He edits WhenIsTheNextEclipse.com, leads tours to see eclipses, and regularly tweets about stargazing (@jamieacarter) and eclipses (@thenexteclipse).

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