The Nikon Monarch M5 12x42 that I've reviewed here also comes in 8x42 and 10x42 versions. They're waterproof, fogproof, and have a sturdy build quality that feels durable in the hand.
The 12x versions are not ideal for eyeglasses wearers due to the slightly more limited 15.1mm of eye relief, but drop down to the 8x and this bumps up to a generous 19.5mm.
Having spent several weeks testing these binoculars in a range of conditions I loved the higher 12x magnification that these versions offer, allowing us to get larger images of far-away birds and other small subjects. However, a middling, average optical performance for their price point ($299/£369) means they don't score quite as highly as some of the other Nikon binoculars I've reviewed in the past.
Nikon Monarch M5 12x42 Specifications
| Design | Roof prism |
| Exit pupil | 3.5mm |
| Eye relief | 15.1mm |
| Weight | 640g |
| Dimensions | 145 x 129mm |
| Magnification | 12x, 10x and 8x |
| Objective lenses | 42mm |
| Durability | Waterproof and fog proof |
Nikon Monarch M5 12x42 Key Features
Fold-back rubber objective lens caps form a tight seal around the glass and I felt confident that they were fully protecting the front elements from rain and dust. Simply strapped around the end of the binoculars it's quick enough to take them off if you prefer not to use them.
15.1mm of eye relief isn't quite enough for some spectacles wearers, but for those that desire this, the 10x versions give a very generous 18.4mm eye relief and the 8x model goes even further with 19.5mm.
The dioptre ring on these binoculars does not lock which isn't surprising compared to some of the competitors at this price range, but it does throw up somewhat of a quandary in my mind when compared to Nikon's own Prostaff P7 range which does have this feature and costs about the same.
Fully waterproof and sealed with O-rings the binoculars perform fine in the rain and snow and can even survive for up to 10 minutes submerged in up to one meter of water.
They're even usable when moving between home and country because they are Nitrogen-purged which prevents internal fogging, a common drawback known to any observer who has used binoculars without this feature.
Nikon Monarch M5 12x42 Build & Handling
A sturdy rubberized armor wraps the entire of the binocular body except for the very ends nearest the eyepieces which change into a hard resin plastic. The eyecups are comfortable and just soft enough to avoid the typical red circle marks one gets when observing for long periods — I like this a lot.
The focusing wheel is knurled and provides ample texture for smooth operation even while I was wearing thick woolen gloves. There's also just enough resistance to avoid accidentally pulling focus too far when tracking moving subjects like birds and planes but not so much that I couldn't fine-tune the focus when needed.
I really like the overall build quality of the Monarch M5 12x42 and found the interpupillary distance range (the adjustable distance between each eyepiece) was amply wide and narrow enough to fit even those with wider or narrower set eyes, even kids.
All the accessories that shipped with the binoculars in the box felt of high quality too. A plush padded neoprene neckstrap was comfortable to wear and the carry pouch that came with it had a leather (or faux leather) strip over the top with an embossed Nikon badge that added a premium feel of the Monarch M5 line.
Nikon Monarch M5 12x42 Performance
Optical quality was perfectly adequate for spotting small subjects with these 12x42 binoculars. Flighty songbirds in nearby trees and medium-sized distant waders were both easy to spot and clearly identified which tells me that the optics resolved detail well. However, I wasn't blown away by the performance in this regard.
At this price, I was hoping for a little more. The Prostaff P3 which I previously reviewed had a surprisingly good optical system for their price, with the P7s following suit and even including features that I'd expect to find on much more expensive models. But the chromatic aberration (color fringing) and coma distortion around the edges of the Monarch M5 12x42 binoculars left us a tad disappointed. This was surprising considering they feature extra-low dispersion (ED) glass inside to specifically reduce chromatic aberration artefacts.
Having said that, I did pick them up a lot when heading out to observe. Many times over other binoculars I had in for review. This was mainly due to the fact that they are very lightweight (640g) and small (145 x 129mm) and the 12x magnification gave me the added reach that the other binoculars did not.
It is rather peculiar to me that Nikon didn't include a locking dioptre ring on the M5 range. The Prostaff P7 (nearly identical in price) does have this feature and the more expensive Monarch M7 range has them also, although they are more expensive. I'm not sure what the reason is for this, but due to this excellent feature not being there and the middling optical performance I'm not confident they'd be the binocular to purchase when compared with the competition at this price point.
Nikon Monarch M5 12x42 Verdict
The Nikon Monarch M5 12x42 binocular are wonderfully lightweight and the roof prism design makes them slim enough to wear all day long without getting weighed down at the neck or finding them tricky to transport.
Average optical quality and a lack of a locking dioptre ring does make them fade into the background though, even compared to Nikon's similarly-priced Prostaff P7 range.
The only time I found myself picking them up was when I wanted extra reach with the 12x magnification and requiring a lightweight binocular for day trips to wildlife reserves. This meant I used them quite a few times but if this won't be your main area of interest when observing I'd recommend looking elsewhere.
Nikon Monarch M5 12x42 Alternatives
If you want the absolute best that Nikon has to offer, I'd highly recommend the almost-faultless Nikon Monarch HG 10x42. Sure, they tip into the four figure range so they are prohibitively out of budget for some observers, but they're built to last, are tiny and lightweight but pack a huge optical punch and are far superior to the M5s reviewed here. In fact, they're some of the best optical instruments I've ever had the pleasure of testing.
Need something much more budget-friendly? At half the price of the Monarch M5s the Nikon Prostaff P3 8x42 might be just what you're looking for. The money is put where it counts: in the optics system. Good brightness and fair views make these a bargain for observers that want to use Nikon due to their optical legacy. But don't expect a premium finish all the way around, especially on the thin neckstrap.
