This Celestron 10 x 50mm Granite ED roof prism binocular is designed for those who want more light-gathering and higher resolution than a 10-power 42mm binocular can provide, but don’t want to pay a high price or big weight penalty to get that added performance. The reasonably-priced 30 ounce Celestron 10x50mm Granite is O-ring sealed and nitrogen purged to shrug off unexpected summer showers and full downpours. It uses costly ED glass in its objective lenses (a rarity in this price range), top quality BaK-4 roof prisms, and phase-corrected multicoated ED glass optics for good high contrast images with excellent color fidelity.
The 10 x 50mm Granite’s field is commendably flat, with images staying in focus from one side of the image to the other. Barrel distortion, the curving of straight lines at the edge of the field, is very modest and well controlled. There is a minuscule amount of chromatic aberration at the very edges of the field, but it is unnoticeable during most observing.
With its 50mm objective lenses providing 42% more light and 19% higher resolution than a 42mm binocular, and its multicoated phase-corrected ED glass optics providing high contrast/high color fidelity images, this 10 x 50mm Celestron Granite binocular can give you the performance edge you’re looking for. Whether you are birding in the fields, woods, or along the shoreline, or are out under the night sky hunting for star clusters, nebulas, and galaxies, this Celestron Granite ED binocular is bound to please.
Features of this binocular . . .
• Roof prism optics. Open bridge H-body roof prism design with internal center focus. High quality BaK-4 prisms for unrestricted light transmission.
• ED glass. ED (Extra-low Dispersion) glass is used in the objective lenses to deliver excellent edge-to-edge sharpness and color correction, while essentially eliminating chromatic aberration for crisp images free from unnatural color fringing. The eco-friendly glasses used throughout this Celestron Granite binocular are lead and arsenic free.
• Broadband multicoated optics. Fully multicoated on all air to glass optical surfaces with multiple layers of ion-deposited broadband antireflection materials for very high light transmission and contrast. With a 5mm exit pupil and 50mm objective lenses, the 10 x 50mm Granite is a bright binocular in twilight or low light situations.
• Phase-coated high transmission prisms. The image-erecting roof prisms are made of high quality BaK-4 glass. The premium grade prisms allow for sharp images, while high transmission multicoatings increase the light throughput to provide the brightest possible images. In addition, special phase-correcting dielectric multicoatings are applied to the roof prisms for peak contrast, color fidelity, and resolution. The resulting improvement is easily seen when looking for color and detail in the shadowed areas of a silhouetted or backlit bird.
• Open bridge magnesium alloy body. The open bridge body design allows the fingers of your hands to wrap naturally around the binocular body for a secure grip in all weather conditions, even when using a single-hand grip. The body is made of magnesium alloy, which is both lighter than aluminum and more rugged to absorb accidental abuse without flinching.
• Waterproof and fogproof. Dry nitrogen filled and O-ring sealed to be waterproof and fogproof in all temperature and climate extremes. Designed to operate reliably in rain forests and deserts alike.
• Armor. Black rubber armor absorbs noise and the bumps and thumps of everyday use and provides a good grip when wet. Thumb recesses and ridges where your fingers naturally fall assure a secure grip.
• Wide field. The field of view is a wide 6.5° (342’ at 1000 yards), quite good for a 10x binocular.
• Twist-up eyecups and good eye relief. The eyecups (metal for long life, not flimsy plastic) are rubber-rimmed for comfort. They twist up to block ambient light and increase contrast for those who don’t wear glasses. They retract for eyeglass or sunglass use. Click stops provide three distinct eyecup heights to let you match the individual eyecup height to your eyes. Eye relief is specified at 17mm, although it typically measures a mm or two less due to the recessed position of the eye lens (from where the eye relief is typically measured). This provides virtually unvignetted viewing for sunglass wearers or those who must wear eyeglasses when observing.
• Eyepiece rainguard and lens covers. A rubber eyepiece rainguard is standard equipment, to keep eyepieces dry in sudden showers. It can be attached to the binocular neckstrap to hang down out of the way to one side when not in use, without danger of its getting lost. Tethered objective lens covers protect the optics during travel or storage. They flip off the optics and hang down under the binocular tubes to stay out of the way when not in use, but can be removed completely if so desired.
• Close focusing. A little under one and three-quarter turns of the large focusing knob moves from a very good near focus of 9.8’ out to the horizon and beyond. Shallow rubber ribs inset into the metal focus knob make it easy to turn the focus knob, regardless of the weather. A 9.8’ close focus is quite useful for woodland birding.
• Rotary diopter correction. A continuously variable rubber-ribbed metal diopter ring on the right eyepiece allows you to match the binocular optics precisely to your individual eyesight for a sharp image.
• Tripod adaptable. For extended no-hands observing, a protective cover on the front bridge unscrews, revealing a 1/4"-20 thread hole for mounting the Celestron 10 x 50mm Granite on an optional photo tripod using an optional tripod adapter #1187.
• Standard accessories. A one and a half inch wide neoprene-padded neck strap for comfortable all-day use and a water-shedding lightly padded Cordura-style nylon and vinyl carrying case with a wide woven shoulder strap are standard equipment.
• Free binocular harness. An unexpected but welcome no-charge bonus is a binocular harness that permits no-hands carrying of the binocular, in addition to taking the strain off your neck by distributing the weight of the binoculars to your shoulders and torso.