More Information  · Supplied Accessories  · Images of Some Features Price $99.95 List Price $147.45 Optical Type Porro Prism Field of view 7° Field of view 1000 yards 367' Exit Pupil 5mm Relative Brightness 25 Twilight Factor 22.36 Eye Relief 10mm Interpupillary Distance 52-72mm Close Focus 26' Weight 30 oz Height 7" Armored Yes Waterproof No Warranty Limited Lifetime

The filters block the light of mercury and sodium vapor streetlights, passing only the blue-green portion of the spectrum where emission nebulas glow the brightest. By blocking the unwanted blue-white, yellow, orange, and red light, the filters darken the sky background to let the relatively undimmed nebulas stand out against the sky with greater contrast. Thumbscrews at the rear of each prism housing rotate the light pollution filters into place for nighttime use as an astronomical binocular. The filters rotate back out of the light paths for daytime use as a conventional binocular.

At 29.5 ounces, the OptiView is quite light for its aperture and can be hand held with relative steadiness. Even so, there is a 1/4”-20 thread socket at the front of the binocular’s central hinge. This allows the OptiView to be mounted on a photo tripod for steadier images, using an optional tripod adapter.

The 10x50mm OptiView provides a reasonable level of high power performance at an exceptionally reasonable price. Its optics, including the BK7 prisms, are fully coated with magnesium fluoride for high light transmission. Images are more than acceptable, with little astigmatism across the central two-thirds of the field. Moderate astigmatism and barrel distortion are present at the edges of the field, which is to be expected at this price range, but they are seldom a problem during use.

Its charcoal gray rubber armor provides a comfortable grip, even in cold and damp weather. The supplied neck strap is quite thin, so adding an optional #1277B wide neoprene neck strap would improve your comfort level during use. The objective lens covers are tethered to the binocular’s center hinge so they can’t get lost in the field. The supplied eyepiece rainguard keeps dew from collecting on the eyepieces in use. It can be attached to the neck strap to prevent its loss, as well. Focusing is very fast, with little more than half a turn of the grooved rubber-coated focusing knob needed to move from close focus to infinity. The close focus is not exceptional, at 26’, so this would not be a general purpose birding binocular. However, it is a viable and economical choice for daytime use at the home with a view of lake, mountains, or harbor. Add in the unique built-in light pollution filters for nighttime observing, and you have a very interesting binocular indeed.