Oberwerk Mariner 8×40 Binoculars Review: 2014 Edition

I'm not the world's best planner. A skywatching trip is likely to be a spur of the moment thing. When a clear, dark night rattles my cage, I need to just "grab and go." And I may not put my binoculars back on the shelf until many days, many miles and many other activities later.

The Oberwerk Mariner 8x40s can take the travel. They excel at astronomy. They're totally small enough to wear for a full afternoon of birding or soccer-match watching. And, as the Mariner name implies, they are waterproof and can absorb an occasional bump from sliding across a boat deck or cabin top, without going out of alignment. That's why we've picked the Oberwerk Mariner 8x40 binoculars as our Editors' Choice for Best Small Astronomy Binoculars.

BUY the Oberwerk Mariner 8x40 binoculars >> - Below: See our Hands On Video Tour of Oberwerk's Mariner 8x40 (Click to Play):

At 5.5 inches (14 centimeters) from front to back and 6.5 inches (16.5 cm) wide, these Oberwerks make a brawny, satisfying handful of tech. If you're new to comparing astronomy binoculars, it may strike you as odd that we're calling these "small." Certainly, there are many smaller, lighter binoculars on the market. What we mean is, "small, but still good for astronomy." And at astronomy, these "binos" excel. [Related: See our Buyer's Guide: How to Choose Binoculars for Stargazing]

At 37 ounces (1 kilogram), the 8x40s are a meaty chunk to wield all night long. But they are quite comfortable. They stay out of the way, even if you are also working a telescope. In fact, I found them to be the perfect complement to a telescope. Use your Mariners to scan a wide sky field for an interesting object or region, then warp yourself in closer with your mono 'scope. If you're into astrophotography, you can enjoy the sky with your Oberwerks while your telescope is busy recording photons (during which time, you will NOT want to touch it).

You'll be impressed at the tack-sharp points of stars and the crisp detail when observing lunar terrain with these Mariners. As you reel in the tantalizingly dim, milky light of other galaxies, or of diffuse star clusters within Earth's own galaxy, Oberwerk's impressively high contrast-ratio will sear those stars into your memory. And you may happily lose yourself for many minutes in the celestial depths of the Mariner's unusually wide 8.4-degree field of view. Your mind may switch from just "skywatching" to virtual sky-walking. That's exactly where you want to be.

Build-quality, optical path and prism design are responsible for the mass factor. These Mariners, like every set of astronomy binoculars we reviewed, use the optically superior "porro-prism" design as opposed to smaller, lighter and less costly "roof prisms." You'll find a few very similar binoculars with other name brands on them, but none with better coatings, quality control, shock protection or water resistance.

As with any optical device, ability to gather light is directly related to aperture (optical opening). For the most part, the bigger the aperture, the better, as long as the light rays remain collimated (aligned). Here, these Oberwerks excel: The nicely coated 40mm objective lenses haul in more photons from faint stars than all but the most expensive competitors.

Stepping outside your home, your binoculars are often required to "equilibrate" to the cooler temperatures of night, especially in wintertime. The Mariners' internal optics are nitrogen-purged, perfectly coated and properly sealed. They will not fog as quickly as most other brands.

If you wear eyeglasses (I do), you'll appreciate the way the guards around the eyepieces work. A quarter-turn rotates them fully up or down. It's easy to get your bespectacled eyes just the right distance from the "exit pupil," the round spot where the image forms. My eyes are set close together. The bridge of my nose started to feel just a little bit pinched, right at the point where I got the exit pupils to resolve into a single stereoscopic image; my only moment of discomfort while observing with these Mariners.