Oberwerk BT-100XL-ED Binocular Telescope

Oberwerk BT-100XL-ED Overview

A Guide to Birding with Binoculars

By Photo’s Morgan Lyle

With magnifying power of 32x and easy, both-eyes-open viewing, the BT-100XL-ED Binocular Telescope from Oberwerk provides a satisfying alternative to traditional telescopes for astronomical or long-range terrestrial observation. The BT-100XL-ED is built with broadband fully multicoated, extra-low dispersion objective lenses that minimize chromatic aberration or color fringing. Unlike a telescope, the optic is fitted with prisms that cause the image to be upright, so you can observe distant ships, breaching whales, and mountain peaks inaddition to celestial objects.

The BT-100XL-ED can be “go-to” automated by using the separately sold iOptron HAZ31 Strain Wave Alt-Az Mount. The eyepieces are angled at 45 for comfortable viewing and the optical tubes have a large interpupillary adjustment range, so everyone from children to adults can enjoy the view. Binocular telescopes are far more portable than standard telescopes and do not require specialized mountsan ordinary tripod with a 3/8″-16 or 1/4″-20 mounting stud will do, provided it is rated for a 12.5 lb payload.

Optical Performance

• Focal length eyepieces are 1.25″, 14mm for 40x magnification which is ideal for long-range terrestrial use or astronomical viewing.
• The 100mm objective lenses help offset the dimming that is common with high-powered optics during the day and to draw in the light required for astronomy use at night.
• The extra-low dispersion objective lenses minimize color fringing.
• Antireflection fully multicoated optics maximize light transmission for bright and clear images with accurate color rendition and improved contrast and clarity.
• The apparent angle of view is a wide 70 and the collimation certified to 140x.

Use and Handling

• Eyepieces are angled 45for comfortable use
• Large 50-80mm interpupillary distance adjustment range accommodates children and adults
• With separately sold iOptron HAZ31 alt-az mount, the BT-100XL-ED can be “go-to” automated
• Lightweight, waterproof, and nitrogen-filled magnesium body
• Handle is a Picatinny rail for accessories such as finders or laser pointers
• Tested and tuned to perfection prior to shipping

In the Box

• Oberwerk BT-100XL-ED Binocular Telescope
• 2 x Eyepiece (14mm 1.25″)
• Aluminum Frame Case
• Limited 3-Year Manufacturer Warranty

Not in the Box

• Essential Tripods & Monopods (Not Included)

• The Binocular Buying Guide

  Christopher Witt

  4 years ago

• Summer Binocular Buying Guide

  Christopher Witt

  8 years ago

• A Guide to Marine Binoculars

  Todd Vorenkamp

  9 years ago

Oberwerk BT-100XL-ED Specs

Key Specs

Performance

Features

General

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