Lanthorn Penumbra 20x56 binoculars, with tripod adapter
20x magnification · 56 mm objectives · 2.4° field
$1,879
Catalog preview. Not available for purchase.
- Package
- With tripod adapter
- Optics
- ED glass, fully multi-coated
- Armor
- Slate gray armor
- Edition
- 2026 edition
Specifications
| Magnification | 20x |
|---|---|
| Objective diameter | 56 mm |
| True field of view | 2.4° |
| Exit pupil | 2.8 mm |
| Dawes limit | 2.07 arcsec |
| Limiting magnitude | 10.7 |
| Eye relief | 16 mm |
| Close focus | 10.0 m |
| Prisms | BaK-4 roof |
| Weather sealing | Waterproof, nitrogen purged |
| Weight | 1,900 g |
| Package | With tripod adapter |
| Optics | ED glass, fully multi-coated |
| Armor | Slate gray armor |
| Edition | 2026 edition |
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
This listing covers one configuration of the Lanthorn Penumbra 20x56 binoculars, defined by its package, optical coatings, armor color, and edition year. The included tripod adapter lets you fix the binoculars to a photo tripod for steadier, more relaxed views. With the adapter on a tripod, hand shake disappears, which makes faint stars and close double stars easier to see. ED glass reduces the color fringing that otherwise appears around bright objects such as the Moon and Venus.
The slate gray finish makes the binoculars easier to find on a dark table than the black armor does. The 2026 edition carries the optics over unchanged and updates small parts such as the caps and the case. 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
- L-shaped tripod adapter
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.