Recently, the binocular market has seen a flood of giant binoculars at prices that were unheard of just a few years ago. In general, giant binoculars are defined as those that magnify the view 10 times or more and have 70-mm or larger front (objective) lenses. It used to be that the least expensive giant binoculars cost in excess of $150, even $200. All that changed not long ago, when the bottom fell out of the price cellar. Now, several companies import giant binoculars that sell for half that, or less.

Celestron's 15x70 SkyMaster binoculars are one of the leaders in the low-price giant binocular arena. They certainly sound good on paper. The SkyMasters include multicoated optics and BaK-4 internal prisms, two features that promise brighter, better images, and key points to look for when judging a pair of binoculars. They also come with an adapter for attaching them to a photo tripod, which is a must to use them to their fullest, and a soft carrying case. But just because they are cheap doesn't always mean they are worth the price. Would it be better to save up for a more expensive pair?

To find the answer, I had an opportunity recently to judge the SkyMasters against a pair of Fujinon 16x70 FMT-SX binoculars , one of the finest pairs of giant binoculars sold today. Like the SkyMasters, the Fujinons feature BaK-4 prisms, but also have fully multicoated optics. As a general rule, superior coatings mean superior image sharpness and contrast. But then, that should be expected, given that the Fujinons cost many times more than the Celestrons.

While the Fujinons were clearly the better performer, the Celestron SkyMasters held up admirably. Image brightness, quality, and contrast were all remarkable considering their bargain price. Although images were a little soft across the outer 25% of the Celestron's field, the overall view was impressive nonetheless.

Some inexpensive binoculars have very sloppy focusing, causing the eyepieces to tilt and shift. Not so with the SkyMasters. I found that their center-focusing mechanism worked smoothly, with no apparently backlash or wobble. Eye relief (the distance you hold your eyes away from the eyepieces to see the full field) is stated to be 18 mm, a good distance for higher power binoculars and an important consideration if you must wear glasses when viewing. The SkyMasters are also light enough to support by hand for short periods of time, although buyers would be well advised to mount them on a sturdy photo tripod.

The bottom line is, if you are considering a pair of giant binoculars, whether for bird watching, stargazing, or another recreational use, and have a limited budget, Celestron's giant 15x70 SkyMasters represent an excellent value. --Phil Harrington, author of Star Ware and Star Watch

Pros:

• Exceptional value for the price
• Light enough to support by hand
• BaK-4 prisms
• Multicoated optics

• Outer 25% of the field is soft and a little blurry
• Requires a tripod to use for extended periods

Specifications:

• Magnification: 8x
• Objective lens diameter: 21mm
• Size class: Compact
• Focus system: Center
• Prism system: Roof
• Prism glass: BK-7
• Lens coating: Fully
• Field of view @ 1,000 yards: 378 feet
• Close focus distance: 21 feet
• Exit pupil: 2.6mm
• Eye relief: 9mm
• Eyecups: Fold down
• Waterproof/fogproof: No
• Adapts to tripod: No
• Weight: 7 ounces
• Warranty: Limited lifetime

Tech Talk
Objective Lens:The diameter of the objective or front lens. The larger the objective lens, the more light that enters the binocular, and the brighter the image.

Field of View (F.O.V.):The side-to-side measurement of the circular viewing field or subject area. It is defined by the width in feet or meters of the area visible at 1000 yards or meters. A wide angle binocular features a wide field of view and is better for following action. Generally, the higher the magnification, the narrower the field of view.

Roof Prism System:In roof prism binoculars the prisms overlap closely, allowing the objective lenses to line up directly with the eyepiece. The result is a slim, stream-lined shape in which the lenses and prisms are in a straight line.

The Model 512 is built to last, with a rugged aluminum hood assembly and knobbed, tool-free mounting bolt. Other features include a 65 MOA circle reticle with a 1 MOA aiming dot; support for two 1.5-volt AA batteries (lithium or alkaline); unlimited eye relief; and 20 brightness settings. The Model 512 is compatible with 1-inch Picatinny or Weaver rails.

Specifications

• Optics: Transmission holography, parallax-free
• Magnification: 1x
• Eye relief: Unlimited
• Waterproof: Submersible to 10 feet
• Sealing: Fogproof internal optics
• Adjustment (per click): 0.5 MOA (1/2 inch @ 100 yards)
• Adjustment range: +/- 40 MOA travel
• Mount: 1-inch Picatinny or Weaver rail
• Return to zero: Repeatable to 1 MOA after remounting
• Display window optical surfaces: Anti-glare coating
• Window dimensions: 1.2 by 0.85 inches
• Front window material: 1/8-inch solid glass
• Rear window material: Shatter-resistant laminate (3/16 inches thick)
• Field of view: 30 yards @ 100 yards at 4 inches eye relief
• Brightness adjustment range: 110,000:1 (brightest to lowest)
• Night vision compatibility: No
• Power source: Two 1.5-volt AA batteries (supports lithium, alkaline, or rechargeables)
• Battery life: 1,000 continuous hours (lithium) at nominal setting; 600 continuous hours (alkaline)
• Brightness settings: 20 with scrolling feature
• Auto battery check indicator: Flashing reticle upon startup
• Auto shutdown: At 8 hours; programmable to 4 hours
• Dimensions: 5.4 by 2.25 by 2 inches (W x H x D)
• Weight: 10.9 ounces

Specifications

• Magnification: 60 to 100x
• Batteries: 3 SG3 button cell (included)
• Dimensions: 1.25 by 3.25 by 0.75 inches (W x H x D)
• Weight: 1.1 ounces

Specifications:

• Baseball/softball/tennis range: 10 to 110 mph (90 feet away)
• Auto racing range: 10 to 200 mph (1,500 feet away)
• Accuracy: +/- 1 mph
• Dimensions: 4.3 by 8.4 by 6 inches (W x H x D)
• Weight: 19 ounces
• Warranty: 2 years

The open sight lets you select from four different reticle patterns and seven unique brightness settings.

Specifications

• 1X magnification
• 33-millimeter objective aperture
• 24 x 34 objective diameter
• Three-inch length
• 4.2-ounce weight