Lanthorn Penumbra 20x56 binoculars

Specifications

Description

The Penumbra 20x56 is a large-aperture binocular for observers who want high magnification with a steady view. Its 56 mm objectives gather enough light to show faint deep-sky objects, and 20x magnification brings the Orion Nebula, the Andromeda Galaxy, and open clusters such as M44 and M35 into clear detail. The true field of 2.4 degrees gives an apparent field of about 48 degrees, so you can scan across star clouds in Sagittarius and Scutum without losing your place.

The exit pupil is 2.8 mm, which suits a dark sky and a fully dark-adapted eye. At 20x, small hand tremors show as image movement, so the 1.9 kg total weight calls for support. Mount the binoculars on a parallelogram harness or a tripod adapter, or rest your elbows on a car roof or a sturdy wall. The central focus wheel moves smoothly, and the right-eye diopter corrects for focus differences between your eyes.

The BaK-4 roof prisms are fully multi-coated, which keeps the image bright and the color neutral toward the edge of the field. Nitrogen purging and O-ring seals resist fogging and moisture, so you can use the binoculars on cold, damp nights. The 16 mm eye relief lets observers who wear glasses see most of the field, though the eyecups should be fully extended. The 10 m close focus lets you check focus on nearby daytime targets before dark.

Begin with the Moon a few days after new, when the terminator shows craters in fine relief. Then sweep along the Milky Way from Cygnus toward Scutum, noting the Dumbbell Nebula in Vulpecula and M11 in Scutum. Return to the same objects on a moonless night to compare how much dark skies change the view. Keep a log of each object, its magnification, and the sky conditions, so the notes help you plan later sessions.

About this configuration

The Lanthorn Penumbra 20x56 binoculars comes in several configurations, and the notes below explain what this particular combination includes. This package contains the binoculars with their strap, lens caps, and case, without any mounting hardware. Binoculars alone suit hand-held scanning of the Milky Way, bright star clusters, and the phases of the Moon. ED glass reduces the color fringing that otherwise appears around bright objects such as the Moon and Venus.

Olive rubber armor offers the same protection as the black version in a different color. This is the 2026 edition, the most recent version of the Penumbra line in the catalog. The magnification, field, and exit pupil figures in the specifications table apply to every configuration of the Penumbra line.

What's in the box

• Binoculars with neck strap
• Objective and eyepiece caps
• Padded carrying case
• Lens cleaning cloth

Compatibility notes

• The central tripod socket takes a standard L-shaped binocular adapter with a 1/4-20 thread.
• Fits parallelogram harnesses rated for 2 kg binoculars.