Nikon Monarch M5 10x42 vs Leupold BX-3 Alpine HD 10x42
Quick take: The Leupold BX-3 Alpine HD 10x42 costs $50 less; the Leupold BX-3 Alpine HD 10x42 has a wider field of view (342 vs 293 ft @ 1000 yds).
Field of view, to scale
Top-down view · drawn to true scale — no exaggeration
Which one to buy
Field of view is the Nikon Monarch M5 10x42's known weak spot, and the Leupold BX-3 Alpine HD 10x42 aims straight at it. The Leupold shows 342 ft at 1000 yards against the Nikon's 293 ft, focuses closer at 6.2 ft against 8.2 ft, uses a magnesium chassis, and costs $50 less. Both weigh 22.6 oz. The BX-3 Alpine HD is the newer model, replacing the discontinued BX-2 Alpine HD and moving the name up a tier, so it has less of a track record.
The Nikon's case is its glass and eyepiece. Owners say its ED glass gives a sharp, color-true, fringe-free image that beat rival mid-range binoculars for edge-to-edge sharpness in owner comparisons, and its 18.4mm of eye relief is outstanding for a 10x and works with glasses. The Leupold has 16mm, and the Nikon adds ED glass and a locking diopter. The Nikon's owners are clear about its faults: a tunnel-like view that makes moving birds hard to follow, a focus wheel some find sticky, and a limited warranty where the Leupold's is a lifetime guarantee.
For hunters who glass a spot and study it, and for anyone in glasses, the M5 is the better optic. For finding and following animals, or for anyone who simply wants a wider window for less money, the Leupold is the easier binocular to live with.
Nikon Monarch M5 10x42
For eyeglass wearers and deliberate glassers who value a sharp, fringe-free image over a wide view, the extra $50 buys better optics.
Leupold BX-3 Alpine HD 10x42
Best if you track moving game or birds and want a much wider view and closer focus for $50 less.
| Spec | Nikon Monarch M5 10x42 | Leupold BX-3 Alpine HD 10x42 |
|---|---|---|
| Approx. price | ~$350 | ~$300 |
| Use case | Hunting | Hunting |
| Magnification | 10x | 10x |
| Objective | 42mm | 42mm |
| Exit pupil | 4.2mm | 4.1mm |
| Field of view | 293 ft @ 1000 yds | 342 ft @ 1000 yds |
| Eye relief | 18.4mm | 16mm |
| Close focus | 8.2 ft | 6.2 ft |
| Prism | Roof | Roof |
| Glass | ED | HD |
| Coating | Fully Multi-Coated | Fully Multi-Coated |
| Weight | 22.6 oz | 22.6 oz |
| Dimensions | 5.6 x 5.1 in | 5.7 x 5.0 in |
| Warranty | Limited Lifetime | Lifetime |
Feature comparison
Nikon Monarch M5 10x42
- ✓ED Glass
- ✓Phase-Corrected
- ✓Dielectric Coating
- ✓Waterproof
- ✓Fogproof
- ✗Image Stabilized
- ✓Tripod Adaptable
- ✗Magnesium Body
- ✓Locking Diopter
Leupold BX-3 Alpine HD 10x42
- ✗ED Glass
- ✗Phase-Corrected
- ✗Dielectric Coating
- ✓Waterproof
- ✓Fogproof
- ✗Image Stabilized
- ✓Tripod Adaptable
- ✓Magnesium Body
- ✗Locking Diopter
What birders say
Nikon Monarch M5 10x42
- ✓ED glass at a mid-$200s price delivers the clean, fringe-free image that separates it from the Prostaff tier - forum testers who ran it against the Prostaff P7 and Vortex Diamondback HD gave the M5 the overall edge-to-edge sharpness win
- ✓Excellent 18.4mm eye relief for a 10x42 - reviewers call it out as genuinely eyeglass-friendly, where most 10x competitors force glasses wearers to compromise
- ✓Owners consistently describe the image as clear, sharp, and true to color - the classic Monarch signature that made this line a best-seller
- ✓Dielectric prism coatings and fully multi-coated optics keep the view bright for a 42mm - side-by-side testers found it brighter than the Vortex Diamondback HD
- ✓Noticeably nicer build than the Prostaff P7 - a forum tester specifically contrasted the M5's solid eyepieces with the P7's rattly ones
- ✓Reasonably light for the class at 22.6 ounces, with a trim body that reviewers say handles closer to a mid-size than a full-size
- ✓Locking diopter holds settings through hard field use
- ✓Owner reviews frequently note it delivers close to Monarch M7 performance for meaningfully less money - the 'sensible Monarch' pick
- ✗The narrow field of view is the complaint that shows up in nearly every review - 293 ft at 1000 yards creates what testers describe as a tunnel-vision feel that makes finding and following birds harder
- ✗The Vortex Diamondback HD 10x42 offers a substantially wider window for less money, which reviewers repeatedly cite as the M5's most awkward comparison
- ✗Focus wheel gets mixed reports - some testers found it needs constant positive pressure to keep moving rather than gliding, though others call it smooth and fast
- ✗The 4.2mm exit pupil dims earlier at dusk than an 8x42 - a real consideration for hunters who need the last minutes of light
- ✗Handheld shake at 10x is amplified by the light body - some users find they need to brace more than expected
- ✗Nikon's limited lifetime warranty is far more restrictive than Vortex's transferable no-fault VIP warranty on similarly priced glass
- ✗Close focus of 8.2 feet is fine for feeder birds, the same as the Monarch M7, but too long for butterflies
- ✗Dedicated birders on forums keep concluding the M5 isn't for them - the field of view issue pushes them to the M7 or wider rivals despite the M5's sharpness
Nikon Monarch M5 10x42 vs Leupold BX-3 Alpine HD 10x42: common questions
Is the Nikon Monarch M5 10x42's narrow field a problem next to the Leupold BX-3 Alpine HD?▾
It can be. M5 owners describe its 293 ft field as tunnel-like and say it makes following moving birds harder. The Leupold's 342 ft is much wider, which helps when scanning for or tracking game.
Which is better with glasses, the Nikon Monarch M5 10x42 or the Leupold BX-3 Alpine HD 10x42?▾
The Nikon. Its 18.4mm of eye relief is unusually generous for a 10x, and owners say glasses wearers see the full field. The Leupold has 16mm, which suits many but not all spectacle wearers.
Does the Leupold BX-3 Alpine HD 10x42 have ED glass like the Nikon Monarch M5 10x42?▾
Leupold calls its glass HD rather than ED, while the Nikon has ED glass, and owners credit it with a fringe-free image. With the Leupold still new and little track record behind it, the Nikon is the safer bet for color correction.