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Full-size Binoculars

Recent Advances in Binoculars

January, 2000, BirdWatcher's Digest)
Some advance reviews of new binoculars
September, 2004

(Michael is carrying his beloved old Zeiss B/GA T binoculars. Diane is holding onto her Swarovski ELs. Photo by Joe Stanski.)

Birding binoculars are the tools of a sacred trade. The visions they reveal create experiences of immeasurable quality.

Birders, perhaps more than any other group, appeciate the intimate connection with nature that their binoculars provide. Forever approaching the beautiful, birders want their optics to be equal to the task.

This heart's desire, along with a robust economy, has driven the market in birding binoculars to produce better and better optics. If you're looking for new birding binoculars, you have better choices today than ever before.

To survey the current state of the art, we asked manufacturers to choose and send us their best full-size birding binoculars. We tested 61 models, whose specifications are included in the accompanying chart.

Pentax waterproof binoxWe also organized a testing day for a dozen experienced birders to judge the binoculars. We'll include the results of the judges' reviews.

It's clear that manufactures have studied what birders want and have responded with a host of improvements in optics and useful features. Here's what's new.

Eyecups past and future
Binoculars you love to touch
Lens caps lost and found
Locking diopter adjustments
The weighty matter of weight
Close focus feats
Infinity -- the other end of close focus
Roof prisms vs. Porro prisms

Eyecups past and future

Consider the small matter of eyecups. A few years ago, nearly all binoculars accommodated eyeglass wearers with folding rubber eyecups. But for birders who share their binoculars, rubber eyecups cause trouble. Most require a bit of wrestling to fold them up or down, costing several seconds each time the binoculars change hands. That can make you miss the bird.

Swarovski ELToday many roof prism binoculars (such as those by Leica, Pentax, and Brunton) have eyecups that neatly slide in and out. A few (such as the Nikon Venturers LX, the Bushnell Legend, and all the Swarovskis, whose new EL model is shown at right) go one better and offer twist-up eyecups that let the user dial exactly the needed amount of eyecup extension. Twist-ups also maintain their position without collapsing at crucial moments.

These new eyecup designs are the future.

Binoculars you love to touch

Nikon Venturer LXToday's binoculars feel good to the hand. Many have a semi-soft, non-slip armoring that protects the surfaces from dings and scratches and cushions the occasional blow. (The Nikon Venturers LX shown at right is a case in point. They are a real pleasure to hold.)

We're happy to see that most of the economical Porro prisms as well as expensive roof prisms now have such skin-friendly coverings.

Lens caps lost and found

Birders often prefer to carry their binoculars around loose, rather than in a never-ready case. Fortunately, the new, waterproof, well-sealed, soft-armored binoculars are quite rugged.

However, expensive optical surfaces still need protection from scratches, so lens caps have become more important than ever before. But sometimes lens caps get lost almost before they're out of the box. Therefore we applaud Swarovski, Steiner, Brunton, and Swift (on the waterproof Trilytes) for ingeniously attaching the lens caps to their binoculars.

Locking diopter adjustments

A binocular's diopter adjustment lets you alter the focus of one eyepiece in order to compensate for any difference between your left and right eyes. With the diopter adjustment properly set, both eyes will comfortably focus at the same distance.

The classical diopter adjustment, still used by most Porro prism and some roof prism binoculars, allows you to turn one eyepiece to adjust its focus. On too many binoculars, however, the slightest bump undoes the adjustment.

Recent improvements in top roof prism binoculars from Nikon, Swarovski, and Bausch & Lomb lock the diopter setting so that it doesn't accidentally get changed. A ring must be pulled or a knob pushed before the diopter adjustment will move. A small but valuable improvement.

The weighty matter of weight

In the past, high quality optics have too often been a pain in the neck. But today we are seeing full-size, lighter-weight binoculars of superb optical quality.

For example, Swarovski has recently designed a new birding binocular, the Swarovski EL, with features that excel its much-admired model SLC. Incorporating a magnesium-alloy housing and weight-saving innovative design, the 10x42 EL weighs only 27.5 oz. This shaves over three ounces off the carry weight of the Swarovski 10x42 SLC and makes it 7 oz. less than the 10x42 Nikon Venturer LX.

Close focus feats

Birders love close focus. We often study birds up close, and when birds aren't available many of us watch butterflies. The closer a binocular focuses, the better we like it.

However, close focus is not a cut-and-dried matter. Close focus varies from person to person through binoculars just as it does with the naked eye. So the distance that the manufacturer quotes is at best a guideline. To determine true close focus, you have to try the binoculars with your own eyes.

Pentax Waterproof BinoxExamples of close focusing binoculars are: Bausch & Lomb 8x42 and 10x42 Elites, Celestron 8x42 Regal and Eagle Optics 8x42 Ranger, Brunton Eterna, Steiner Rocky S, Swarovski's new EL series, Pentax DCF Waterproof (shown at right), and Bausch & Lomb 7x26 Custom Compact. All these can focus as close as 8 feet or closer.

Infinity -- the other end of close focus

Infinity and close focus are connected. Every binocular design has a range of focus, from close to infinity. Actually, most let you focus past infinity. This is necessary because human eyes vary, and viewers dial infinity at different places on the focus knob. To accommodate all eyes there must be range room beyond infinity.

There's also another reason to go beyond infinity. We focus by going past the point of sharpness, until the image blurs. Then we back up to the optimum focus, satisfied that the image is as good as it gets.

Now there are two ways to produce close-focusing binoculars. One is to design the optics from scratch with a greater range of focus. The other is to tweak an existing binocular design by moving its whole range of focus closer. That method steals some of the range from the infinity end.

Note that, for some viewers, a binocular design thus tweaked might not focus sharply on distant objects. So when buying a close focusing binocular, be sure to try it at infinity as well as up close.

This article is reproduced here with permission of BirdWatcher's Digest, where it first appeared, in January, 2000.





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