Northmere Tundra 15x100 ED binoculars, with parallelogram mount

Specifications

Description

The Tundra 15x100 ED binoculars pair 100 mm objectives with 15x magnification, which gives an exit pupil of about 6.7 mm. The large aperture gathers enough light to show faint star clusters and bright nebulae under dark skies, and the exit pupil suits observers whose dark-adapted pupils open wide. Extra-low-dispersion glass in the objectives reduces color fringing around bright stars and the lunar limb.

A true field of 4.0 degrees gives an apparent field of about 60 degrees. Star fields in Cygnus, Sagittarius, and Scorpius fill the view, and the Pleiades, the Double Cluster in Perseus, and the Orion Nebula fit within the field with room to spare. At 4.2 kg, the binoculars are too heavy for steady hand-held use at 15x, so mount them on a tripod with a rotating adapter that keeps the eyepieces level as you change altitude. The 20 mm eye relief lets you keep your glasses on and still see the full field, and the 10 m close focus lets you view nearby ground objects.

The body is nitrogen-purged and waterproof, so the optics resist fogging and remain usable in damp conditions and during dew formation. The central focus wheel moves through a long travel for precise focus at this magnification, and the right-eye diopter corrects for differences between your eyes. To check alignment, center a bright star and switch between eyes; the star should stay centered in both views.

Use a tripod with a payload rating well above 4.2 kg, and set it on firm ground to limit vibration. Start with the Moon to test focus and sharpness, then sweep along the Milky Way from Cygnus toward Cassiopeia. Note which clusters and nebulae you can resolve, and return to them on a darker night to compare the difference that sky transparency makes.

About this configuration

All configurations of the Northmere Tundra 15x100 ED binoculars share the same magnification and objective size; the options below change the package and finish. The parallelogram mount keeps the binoculars at eye level while you move them across the sky in smooth arcs. A parallelogram mount lets observers of different heights share the same view without aiming the binoculars again. With fully multi-coated optics, bright stars show less ghosting and the background sky looks darker.

The tan armor is easy to spot when you set the binoculars down on the grass in the dark. This is the 2023 edition of the Tundra line, the earliest version that is still listed in the catalog. The magnification, field, and exit pupil figures in the specifications table apply to every configuration of the Tundra line.

What's in the box

• Binoculars with center-post tripod adapter
• Objective and eyepiece rain caps
• Padded carrying case
• Neck strap
• Lens cleaning cloth
• Parallelogram mount with counterweight
• Tripod adapter

Compatibility notes

• The central tripod socket takes a standard 1/4-20 adapter with a rotating L-bracket.
• Requires a mount with a payload rating of at least 6 kg, such as a heavy-duty fork or parallelogram mount.