Comparing Four 10×42 Roof Prism Binoculars

Also see Alan Dyer’s comparison of 8×42 roof prism binoculars

In the binocular world, a 10×42 is perhaps the most popular size as it is well-suited for all applications, including astronomy. I test a group of four low- to mid-priced 10x42s under the stars.

If there’s one size of binocular that can do it all, it would be a 10×42. The 42mm aperture lenses gather enough light to be suitable for stargazing, while the 10 power resolves star clusters and lunar features well, more so than an 8×42. The size is also the most popular among nature enthusiasts — compared to an 8×42 the extra power is great for bird identification and wildlife spotting. Yet the 42mm size keeps the binocular light, compact and easy to carry. The downside of any 10x binocular is that it is harder to hold steady than a 7x or 8x glass, to take full advantage of its more detailed views.

In this survey I looked at 10×42 models from $150 to $500, putting them in a low- to mid-range price class for roof prism binoculars. (In case you think $500 is costly, the top-of-the-line is represented by Swarovski’s new 10×42 NL Pure, for $3,400!)

I present them in order of increasing suggested U.S. retail price, though they might sell for less at some outlets. For a survey of a selection of lower-power 8×42 models, see my review here.

Meade Instruments Rainforest Pro

MSRP $160

Pros:    Good field of view and little false color.

Cons:   Soft in outer area of field.

Meade’s Rainforest Pro series is a terrific value. The 10×42 offers a 62° apparent field that’s sharp over the central 60 percent, softening in the outer 40 percent and getting fairly aberrated at the very edge, to be expected at a low price point. Despite not having ED glass, there’s little false color. On-axis star images look fairly sharp with just a trace of softness and spikiness from spherical aberration and astigmatism, aberrations that become more obvious at 10x and higher powers.

The edge-of-field stop is well defined, with just a bit of darkening around the periphery. Construction is solid and the body features a grippy textured surface. Focusing is smooth and precise, while the right-eye diopter has positive click stops for ease of adjustment. However, unlike the more costly 10x42s, the Meade’s focusing mechanism did stiffen enough under freezing conditions that it became hard to turn.

Bottom Line: Excellent, low-cost all-purpose binoculars.

Leupold BX-2 Alpine

MSRP $325

Pros:  Sharp images on and off-axis; light weight.

Cons: Shortest eye relief of the group; some false color.

Like Vortex, Oregon-based Leupold primarily serves the hunting market. The BX-2 Alpine is their lower mid-range binocular series. Without ED glass, some false color is visible when racking through focus on bright stars, but is not objectionable. The edge of field is well defined and illuminated. The 62° apparent field is sharp over the central 70 percent.

The focusing is smooth and precise. The eyecups click firmly into position and stay put under pressure. While eye relief is only 14mm, seeing the entire field with the eyecups retracted was no problem when viewing with eyeglasses. The magnesium construction makes for a light weight of 685 grams, the lightest of the 10x42s, with the Nikon Monarch a close second. Along with the Nikon, the Leupold can collapse to the narrowest interpupillary distance of the group, so either might be a good choice if you have closely-set eyes.

Bottom Line:    Excellent performance for a lower mid-range price.

Vanguard Endeavor ED II

MSRP $400

Pros:  Wide field of view and sharp nearly to the edge.

Cons: Heavier than other models; loose focusing.

Vanguard is a name well known among birders. Uniquely, Vanguard binoculars are made in Myanmar with Japanese optics. In their 10×42 Endeavor ED II images are sharp across 75 percent of the generous 65° FOV, almost as wide as the Nikon Monarchs. Star images are still well contained at the edge, though with a slight darkening of the edge of field at night. Images snap assuredly into focus, with just a trace of false color when racking through focus on the Moon and Venus, but none on bright stars.

The focuser turns smoothly, but with too little resistance, so is easy to shift off focus by accident. On the other hand, the Vanguard is the only binocular I tested that has a lockable diopter setting on the right eye, a welcome feature. Unique among the models tested, the Endeavor series uses an open- or dual-bridge design which makes them easy to hold. However, at 775 grams, this is the heaviest of the 42s.

Bottom Line:   Superb optics and handling for a mid-range price.

Nikon Monarch 7

MSRP $500

Pros:    Sharp, contrasty optics with a wide field of view.

Cons:   Eyecup positions not firm; diopter adjustment tight.

Nikon offers a huge range of binoculars in both Porro and roof prism designs. Nikon’s Monarch 7 is a cut above the $300 Monarch 5 10×42. While both have brighter dielectric coatings on the reflective prism surfaces, the Monarch 7 adds ED glass. Views of starfields were contrasty, with no glare apparent when looking close to the Moon. Stars are pinpoint over 80 percent of the wide 67° apparent field, the best performance of the group.

The edge of field is sharply defined and well illuminated. On-axis, stars snap into tight focus. Indeed, until you use a top-class glass like the Monarch or Vanguard, you don’t realize how soft stars are in many lesser binoculars. The Monarchs are compact and solidly built, with silky smooth focus. However, the right eye diopter adjustment is stiff and hard to turn without affecting the interpupillary distance. The eyecups, while having firm click stops, collapse too easily under pressure. The rear eye caps are also cheap, inflexible plastic; even the low cost Meade has better fitting eye caps.

Bottom Line:   Superb optics in a compact, mid-range binocular.

TABLE: 10×42 Roof Prism Binoculars

Weights are measured with captive front lens caps attached as you would likely use them, so will differ from published specs. Eye relief is measured from the top of the retracted eyecup, not from the lens. Actual fields of view were measured by looking at starfields; the apparent field figure assumes 10x power.