O4B Scorecard

Introduction | How the Scorecard Works

Check here if you wear eyeglasses

Parameter Pref. Celestron 8x42 Bk Choose... Choose... Choose...
Eye Relief 17
Close Focus 6
Weight 22
Field of View 388
Weatherproofing Waterproof/Nitrogen Purged
Eye Cups Twist-up with Detents
Lens Coatings Fully Multi-coated
Prism Material Phase-coated BaK-4
Class (Ref.) 2


  1. Select binoculars by clicking the "Run O4B Scorecard" link on product pages while surfing the site.
  2. This table is limited to four binoculars. To remove a binocular, click on the "Remove" link at the bottom of the appropriate column above. To change to a different binocular, first remove a binocular from the comparison, then follow step 1 to add the new one.
  3. Set your preference factors by adjusting the numbers in the preference column from 0 (irrelevant) to 10 (most important).
  4. If you wear eyeglasses when you use binoculars, check the Eyeglasses box.
  5. If you want more information about a specification, click on its title for a definition and a link to an expanded discussion.
  6. For an explanation of Class and to learn how scores are determined, see How the Scorecard Works.

Learn About Optics

Day Optics

Designs - Quality, compacts, porro and roof prism designs for binoculars and scopes...
Designations and Considerations - Designation values, eye relief, weight & cups, exit pupil, and twilight factor...
Additional Consideration - Focusing, field of view, depth of field, weather proofing and nitrogen fill...
Optic Components & Image Quality - Lenses, mirrors, coatings, aberrations, distortions, and alignments...
Spotting Scopes - Construction, Objective lens, eyepieces, angled or straight, and focusing...
Tripods - Heads, legs, monopods, shoulder stocks, and window mounts...
Digiscoping - About, power, editing, considerations, cameras, techniques, and effects...
Care & Tricks - Holding techniques, cleaning, carrying, and protecting your optics...

Night Vision

Starlight Technology - NV Types, Starlight Technology defined, basic design and IR Illuminators...
Starlight Technology Night Vision Generations and Devices - Generation 1 to 4 - levels of NV technology, types of devices and their uses...
Use & Care - How to use, controls, and care for NV devices, extending capabilities...
Digital Night Vision and Thermal-Imaging - Digital NV and Thermal Imaging, how they work and compare to standard NV...

Buying Guide

Binoculars - All the factors to consider when buying binoculars.
Bins for kids - Special Considerations for children's binoculars.
Challenged - Special considerations with binoculars for the physically challenged.
Spotting Scopes - All the factors to consider when buying a spotting scope.
Tripods - Selecting the best tripod for your scope.
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