Vortex Triumph HD 10x42 vs Diamondback HD 10x42

Field of view

The Triumph HD 10x42 leads. Vortex prints 334 ft at 1,000 yd (6.4 degrees) for it and 330 ft at 1,000 yd (6.3 degrees) for the Diamondback HD 10x42.

Among the 87 models of this size, the Triumph sits at place 46 and the Diamondback at place 47, with a median of 336 ft. Both land close to the middle of the size.

Eye relief and glasses

The Triumph leads again with 17 mm against 15 mm for the Diamondback. The RSPB shop says eyeglass wearers should look for at least 16 mm, and only the Triumph clears that line.

The Diamondback's 15 mm sits at the low end of the 15 to 20 mm that the National Audubon Society gives for binoculars made for birders. The median for this size is 16 mm. If you wear glasses, see binoculars for eyeglass wearers or run your own numbers in the eyeglass eye relief tool.

Close focus

The Diamondback wins this round by a wide margin. Its close focus is 5 ft, while the Triumph's is 15.3 ft. The median for the size is 7.5 ft, so the Diamondback focuses closer than the typical 10x42 and the Triumph does not.

That matters for butterflies, dragonflies and anything else a few steps away. With the Triumph you need to stand farther back before the image sharpens.

Brightness at dusk

The two are equal. Both have a calculated exit pupil of 4.2 mm, a calculated twilight factor of 20.5 and a calculated relative brightness of 17.6. Nikon defines exit pupil as the effective objective diameter divided by magnification, and says a larger one gives a brighter view in dim light.

With the same 42 mm objectives and the same 10x magnification, the sums come out the same. Any difference you notice in the field would come from coatings and glass, which these figures do not capture.

Weight, build and fit

The Diamondback is lighter at 21.3 oz against 22.9 oz for the Triumph. The median weight for the size is 24.9 oz, so both come in under it.

Both are roof prism designs with center focus, and both take a tripod adapter. Vortex lists the same weather wording for each. The Triumph is nitrogen filled and the Diamondback is argon filled. Celestron describes nitrogen-filled optics as an added barrier against internal moisture.

Eye spacing runs 55 to 75 for the Triumph and 55 to 73 for the Diamondback, so the Triumph spans slightly wider faces. For a tripod, see tripod adapters for binoculars.

Price band

Vortex puts the Triumph HD 10x42 in the $100 to $200 band and the Diamondback HD 10x42 in the $200 to $500 band. The cheaper model has the longer eye relief and the wider field. The dearer model has the closer focus and the lower weight.

For more in each band, see binoculars from $100 to $200 and binoculars from $200 to $500.

Triumph HD 10x42 or Diamondback HD 10x42

The Triumph HD 10x42 takes field of view (334 ft against 330 ft) and eye relief (17 mm against 15 mm). The Diamondback HD 10x42 takes close focus (5 ft against 15.3 ft) and weight (21.3 oz against 22.9 oz). Dusk brightness is level, so your own use decides.