Razor UHD 10x42 vs NL Pure 10x42

Field of view

Here the Swarovski leads. It shows 399 ft at 1,000 yd, or 7.6 degrees, and it sits second among the 87 binoculars of its size with a field figure. Vortex's Razor UHD 10x42 shows 346 ft, or 6.6 degrees, which puts it 18th of 87.

Both clear the size median of 336 ft, but the Swarovski clears it by far more. At the same 10x magnification, the extra width gives you more scene around a moving bird or animal.

Brightness at dusk

The two are equal. Both are 10x42, so the exit pupil works out to 4.2 mm, the twilight factor to 20.5 and the relative brightness to 17.6. These are calculated from the size, not printed by the makers.

Nikon defines exit pupil as the objective diameter divided by magnification and says a larger one gives a brighter view in dim light. With identical sizes, any dusk difference between these two would come from glass and coatings, which the makers' figures here do not quantify.

Eye relief and glasses

With 18 mm of eye relief against 16.7 mm, the Swarovski NL Pure 10x42 leads. The RSPB says eyeglass wearers should look for at least 16 mm, so both qualify.

Both also sit above the size median of 16 mm. Swarovski Optik says high-quality binoculars offer 14 to 19 mm, and the NL Pure sits near the top of that range. If you wear glasses and want the most room, the Swarovski gives it. See the binoculars for glasses wearers list for other options.

Close focus

Close focus goes to the Vortex. It focuses down to 4.5 ft, while the NL Pure 10x42 reaches 6.6 ft. The size median is 6.6 ft, so the Vortex focuses closer than the median and the Swarovski matches it.

That matters for butterflies, dragonflies and other subjects at arm's reach. That lets you step closer before the image goes soft.

Weight and handling

At 30 oz, the NL Pure 10x42 is lighter than the 32.2 oz Razor UHD 10x42. Both are well above the size median of 24.9 oz, so neither is a light carry for its size.

Both are tripod adaptable. Vortex gives the Razor center focus and a 56 to 76 eye spacing range, wider than the 56 to 74 printed for the Swarovski, which helps if your eyes sit far apart.

Build and weather sealing

Vortex fills the Razor UHD with argon and describes it as designed to withstand harsh weather conditions. Swarovski prints no gas or sealing figure for the NL Pure 10x42, so neither model leads here.

Celestron says waterproof binoculars are sealed and filled with dry inert gas. Nikon adds that waterproof binoculars should not be used underwater. Vortex builds the Razor UHD as a roof prism, and both models carry a maker list price band of over $2,000.

Razor UHD 10x42 or NL Pure 10x42

Swarovski's NL Pure 10x42 wins four rounds on its figures: view width, eye relief, weight and a printed water depth. Vortex's model wins close focus at 4.5 ft and offers the wider eye spacing range. Brightness is a tie at 17.6 relative brightness.