William Optics 2 x 42mm Cat Eyes Binoculars
- 2x Magnification
- 42mm Objective Lenses
- Ultra-Wide 30° Field of View
- Individual Eye Focus System
- -700° to +300° Diopter Adjustment
- M44.5 x 0.75 Filter Threads
The William Optics 2 x 42mm Cat Eyes Binoculars deliver an immense 30° field of view using just 2× magnification through large 42mm objective lenses. An individual focus system and a massive -700° to +300° diopter adjustment range allow for precise, personalized focus, while the interpupillary distance adjusts from 50mm to 74mm to fit a wide range of observers.
Standard astronomical binoculars offer a field of view around 7°; the Cat Eyes provide a staggering 30°. This isn't an incremental increase—it's a fundamentally different way of seeing the sky. At just 2x magnification, you can frame entire constellations like Orion or Cygnus in a single, sharp view, providing a "spacewalk" feeling of immersion that high-power instruments cannot replicate. This expansive view also makes them ideal for concerts, sporting events, or theater, where you want to see the entire stage or field at once.
Instead of a central focus wheel, the Cat Eyes binoculars feature an individual focus system for each eye. This allows for more precise and durable focus settings that won't shift during use. The key benefit is the enormous -700° to +300° diopter adjustment range, which allows many observers with prescriptions for nearsightedness or farsightedness to achieve a perfectly sharp image without wearing their glasses. Combined with an interpupillary distance range of 50mm to 74mm, these binoculars provide a comfortable, customized fit for almost any user.
The 42mm objective lenses feature full multi-coatings to maximize light transmission and contrast, delivering bright images even in low-light conditions. A critical feature for astronomers is the inclusion of M44.5 x 0.75 filter threads on the front of each objective. This allows you to thread in a pair of nebula filters, such as UHC or OIII filters, to dramatically increase the contrast of emission nebulae against a dark sky background. For added flexibility, optional adapters can convert these threads to the more common M48 standard.
The 2x magnification is a deliberate design choice to achieve the ultra-wide 30° field of view. These binoculars are not for resolving planetary detail but for providing an immersive, wide-field experience. The low power also makes the view incredibly stable and easy to hand-hold, creating a relaxing "spacewalk" sensation as you scan the sky.
They are exceptional for this purpose. The large 42mm objective lenses gather significant light, while the 30° field allows you to sweep through vast sections of the galactic plane, from the Cygnus Rift to the dense star clouds in Sagittarius. You can trace the dark lanes and bright star fields in a way that feels like you're looking through a spaceship window.
They are perfectly suited for meteor showers. The vast 30° field of view means you are monitoring a huge patch of sky simultaneously, dramatically increasing your chances of seeing a meteor's full trail without needing to move the binoculars. The bright, high-contrast optics will make even faint meteors pop against the background.
Yes. Each of the 42mm objectives has M44.5 x 0.75 threads, allowing you to attach filters directly. This is a significant advantage for viewing emission nebulae like the North American Nebula (NGC 7000). Using a pair of narrowband or UHC filters will dramatically enhance contrast. Optional adapters are also available to step up to the M48 filter standard.
With a diopter adjustment range of -700° to +300°, many users can achieve sharp focus without their glasses. The individual focus mechanism for each eyepiece allows you to precisely correct for differences between your eyes, providing a comfortable and immersive viewing session.
An individual focus system, where you focus each eyepiece separately, is generally more robust and precise than a central focus knob. Once set for your eyes, the focus is less likely to be accidentally shifted. This system is also essential for accommodating the wide diopter range these binoculars offer.
| Magnification | 2× |
| Objective Lens Diameter | 42mm |
| Field of View | 30° |
| Focus System | Individual |
| Coatings | Fully Multi-Coated |
| Interpupillary Distance | 50mm – 74mm |
| Diopter Adjustment | -700° ~ +300° |
| Filter Thread | M44.5 x 0.75 (both objectives) |
| Optional Adapter | M44.5 to M48 Filter Adapters |
Cat Eyes 2x42 Binoculars
× 1
Objective Lens Caps
× 2
Eyepiece Caps
× 2
Neck Strap
× 1
Carrying Case
× 1