Porro Prism Binoculars

More Information  · Supplied Accessories  · Recommended Accessories  · Images of Some Features Price $84.95 List Price $119.95 Optical Type Porro Prism Field of view 5.6° Field of view 1000 yards 294' Exit Pupil 5mm Relative Brightness 25 Twilight Factor 22.36 Eye Relief 20mm Interpupillary Distance 56-72mm Close Focus 25' Weight 36 oz. Height 7.5" Armored Yes Waterproof Yes Warranty “No-Fault” Limited Lifetime

Image quality is quite good, with minor curvature of field and very little geometric distortion. Chromatic aberration is surprisingly low for a 50mm binocular. Colors are bright and vivid, and small details are sharply defined, as you would expect from the big high resolution light-gathering lenses. Not exactly a lightweight, at 36 ounces, this Celestron 10x50mm Nature porro prism is nevertheless a good high power binocular at a very reasonable price. It will keep giving you crisp, highly detailed long distance images for years to come,

Features of this binocular . . .

Porro prism optics. Traditional porro prism design using quality BaK-4 prisms. Center focus.

Fully multicoated optics. The optics are treated on all air-to-glass surfaces with multiple-layer antireflection coatings for good light transmission and high contrast.

Waterproof and fogproof. O-ring sealed and nitrogen-purged to be fully waterproof and fogproof in summer showers and monsoon rains alike (although probably not fully submersible).

Armor. Black rubber armor on the rugged aluminum body absorbs noise and shock. Textured gripping surfaces provide a good grip when wet.

Twist-up eyecups. The rubber-rimmed eyecups twist up for use without glasses and twist back down for eyeglass or sunglass use.

Very long eye relief. Eye relief is specified at a full 20mm, although will typically measure a mm or two less due to the eyepieces being recessed to keep them from getting scratched in use. Vignetting should not be an issue for eyeglass wearers.

Close focusing. Focuses only down to 25’, making it definitely better suited for long distance observing than for close-in birding.

Focusing. Not a particularly fast focuser, as about one and three-quarters turns of the ribbed focus knob are needed to move from the 15’ close focus out to the horizon and beyond. Better suited at leisurely sweeping of the landscape, rather than keeping track of fast-moving birds in flight.

Wide field. For a 10x binocular, the field of view is a more than reasonable 5.6° (294’ at 1000 yards), making this Celestron 10 x 50mm Nature Series great for sweeping wide open expanses of fields, marshes, shore lines, and the sky.

Rotary diopter correction. A variable 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, using a tripod to support the Celestron 10 x 50 is virtually a must due to the binocular’s 36 ounce weight. A protective cover on the center hinge unscrews, revealing a 1/4"-20 thread hole for mounting the binocular on an optional photo tripod using an optional tripod adapter.

Standard accessories. An eyepiece rainguard, tethered flip-down objective lens covers, and a soft nylon carrying case with shoulder strap are standard equipment. A very narrow cloth neckstrap is also provided, but our feeling is that it is much too narrow to be comfortable for any extended use. We recommend that the standard neckstrap immediately be replaced by an optional wide neoprene neckstrap, like one of those shown below.

Lifetime warranty. This Celestron Nature Series has a lifetime no-fault warranty. If it breaks or becomes unusable, no matter how it happens or whose fault it is, Celestron will repair or replace the binocular for just a $25 shipping and handling charge. For full warranty details, click on the Warranty Information link at the left of this page and then click on the Celestron link.