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Mid-Sized Binoculars

Part II of Our Birding Binocular Hands-On Field Tests

Pick up a new, top quality, mid-sized binocular-one with objective lenses of 30 to 32 millimeters-and you're bound to be impressed. For starters, you need only one hand, because it's lighter, thinner, and a lot shorter than its 42mm big brother. It's not just easier to carry-it's easier to handle, as well. And because it will fit in your purse, coat pocket, or glove compartment, you're more likely to always have it with you.

It's got the desirable features of contemporary full-sized binoculars: rugged construction, neatly adjustable eye cups, rubberized armoring, waterproofing, close-focus, and anti-reflective coatings. And it seems just as bright and sharp, too. Now look at the price tag. It's cheaper than the big guy.

So why not just forget about full-sized binoculars and buy a pair of mid-sized? Seems like you have nothing to lose but some of the weight around your neck. So what's the catch? Will a mid-sized binocular fail to serve you as well as a full-sized one?

Well, it depends.

Two things you get less of when you go for a mid-sized binocular are exit pupil size and eye relief. How much these sacrifices will cost you depends on who you are-most especially how old you are and whether or not you wear glasses.

THE EYE OF THE BEHOLDER

As we age, it's normal for the maximum pupil size of our eyes to shrink. Imagine Sonny, Dad, and Grandpa at midday, looking at the ducks on the lake. At age 20, Sonny's pupils might be as much as 4.7mm in diameter. Dad, age 50, would show smaller pupils of around 3.5mm. And Grandpa, at 80, would have the smallest pupils, perhaps only 2.3mm.

If they stood there until dusk and into night, the differences between their eyes would become even more dramatic. Over the course of an hour, Sonny's pupils would probably expand until they were 7 or even 8mm, whereas Dad's would grow only to 5mm. Grandpa's pupils would barely react to the darker conditions and might get no larger than 2.5mm.

Binoculars have a pupil size, too. It's called the exit pupil. If you hold your binocular away from your eyes, toward the sky or a bright window, you see the exit pupil as that little circle of light coming out the eyepiece. That's the light your eye will receive when you look through the binocular.

Mid-sized binoculars deliver smaller exit pupils, but that may not make any difference. If the pupil of the eye is contracted to a smaller diameter than the exit pupil of the binocular, the light falling outside the area of the pupil cannot be seen. So for most people, in bright daylight a mid-sized binocular will seem just as bright as a full-sized binocular. For an older person, there might not be much difference even at dusk.

When things are jiggling around, however, it can be useful for the exit pupil to be a little larger than the pupil of your eye. If you're bouncing about in a boat or being buffeted by wind, a binocular with a larger exit pupil helps you keep the binocular positioned where you can see the image. A larger exit pupil can also benefit a person whose hands are unsteady.

The best way to determine whether a mid-sized binocular will give you an optimum birding experience is to try it out in person. Try it in daylight. Try it at dusk and in the darkest conditions you expect to be using it. Remember that it takes at least a half-hour for the eye to become fully darkness adjusted. You can't just switch out the lights and immediately compare the brightness of two binoculars.

In daylight tests our judges found little or no brightness advantage in the full-sized binoculars over mid-sized ones of comparable quality. In the dim light of very early dawn, with eyes fully darkness-adjusted, we found that most of the full-sized binoculars did give us a brighter and more detailed image than the mid-sized ones.

Don't assume that a larger binocular will necessarily give you a brighter picture. The advantages of a smaller, lighter binocular are impressive enough to make it worth serious consideration. Another approach is to own two binoculars, a mid-sized binocular for daytime birding and a full-sized one for dusk or night excursions.

EYE RELIEF

But not so fast. Before you rush off to buy mid-sized binoculars, please consider the matter of eye relief. Bright as the mid-sized binoculars were, some of our glasses-wearing judges found they couldn't see the whole picture through them. "I feel like I'm looking through a pair of tiny tubes," one woman remarked. "Or like someone has painted a black ring around the lens, so I can't see the edge of the picture." She was experiencing the limitations of the binocular's short eye relief.

Eye relief is the distance from the eyepiece to the point where the eye should be positioned in order to let you see the whole picture. People who wear glasses often have trouble using binoculars, because their glasses hold the binocular's eyepiece too far away from their eyes. It's a problem with many binoculars, but particularly with smaller ones.

In recent years, manufacturers have begun to address this problem in full-sized binoculars. They've increased the eye relief and have developed eye cups that have click stops so that the viewer can dial the precise amount of eye relief needed. However, most mid-sized binoculars could still stand improvement in eye relief. In our tests, most of the glasses-wearing judges experienced at least some limitation in their field of view when using the mid-sized binoculars. Furthermore, the eye relief situation is worse with 10x than with 8x binoculars, because higher magnification requires an eyepiece with a shorter focal length, and that results in shorter eye relief.

People who need glasses but do not have astigmatism can look through binoculars without their glasses, adjusting for their nearsightedness or farsightedness merely by focusing the binoculars. For them, one solution is to take their glasses off before raising the binoculars to their eyes. It's a technique with drawbacks-one of which is missing the bird while fooling around with the glasses. Of course, if you wear contact lenses or don't need glasses at all, the eye relief issue won't matter.

It makes a difference how a person's glasses fit. Eyeglasses that fit close to the eyes offer less interference than glasses that ride far out from the eyes. Some people who wear glasses purchase a special pair of glasses for birding. Glasses with small lenses can fit snugly under the brows, almost touching the eyelashes, and allow the binoculars to rest close to the eyes. That may be enough to put the binoculars at the proper distance for the person to see the whole picture.

Bifocals can make viewing through binoculars tricky, as the part of the image seen through the bifocal section won't be in focus at the same time as upper part of the image. Experienced binocular users position their binoculars so that they can look only through the main part of their glasses. Non-line or progressive bifocal glasses make it almost impossible to focus binoculars. If you're getting special glasses for birding, be sure to get "line bifocal" glasses. It may also help to request that the bifocal be a small section at the bottom of the glasses, just enough for consulting the field guide.

It is challenging, but not impossible, to design mid-sized binoculars with long eye relief. It requires extra glass in the eyepiece. One manufacturer told us that his company had not opted for long eye relief in its high-end mid-sized binoculars because they considered non-glasses wearers to be their primary customers for the product. We think that the birding marketplace is likely to change all that. In this era many people have the leisure to pursue birding in later years of life, when they're likely to wear glasses. For this glasses-wearing segment of the population, eye relief is an important issue. And it's an opportunity for manufacturers.

By way of example, the Celestron Noble 8x32 was one of the best in eye relief of all the binoculars we looked at. With its eye relief of 20mm, it affords the full field of view, or very close to it, even to glasses wearers. The new Zeiss 32mm Victory FL also admirably addresses this market. We look forward to more mid-sized binoculars with this capacity.

Mid-sized binoculars have much to recommend them. For travel, when weight is a factor and space is at a premium, the smaller binocular may make the trip when the larger one would get left at home. Furthermore, many people with small or delicate hands find the mid-sized binocular more comfortable than a full-sized model. They're also good for children who are interested enough in birding to need a good binocular.

Binoculars are getting better and better, to the point that differences in optical quality are often eclipsed by ergonomics and the fit and feel of an individual model. What feels comfortable to a person is a personal, individual matter. Maybe one of these new mid-sized binoculars-smaller, lighter, and cheaper-is right for you.

BINOCULARS OF NOTE

In this survey, we found less difference between binoculars than we observed a few years ago. Manufacturers have been converging toward a high standard of design and optical quality. Close-focusing, waterproof, nitrogen-purged, phase-corrected, rubber-armored binoculars are the order of the day. As far as optical coatings are concerned, the secrets are out, and manufacturers have access to similar technologies. Comparing the top binoculars, we found the optical quality quite even. We were also surprised to find that the mid-priced binoculars approached the quality of the greats much more closely than we'd expected.

In the following accounts we have included scores for the models we looked at, representing a subjective overall impression of each binocular's quality. Because the issue of eye relief has such great importance to a person who wears glasses, especially with mid-sized binoculars, we assigned two scores for each instrument: one for use without glasses and one for use with glasses. The highest possible score is 10.

The mid-sized binoculars we reviewed are listed below in alphabetical order. All are roof-prism design. All are waterproof, nitrogen-purged, and phase-corrected. Each one normally comes with case, neck strap, and lens caps.

• Alpen Apex 8x32
• Brunton Eterna
• Celestron Noble 8x32
• Eagle Optics Ranger
• Leica Trinovid BN 8x32
• Leica Ultravid 10x32
• Leupold Wind River - Katmai 10x32
• Minox BD 8x32
• Nikon Premier LX 8x32
• Pentax DCF XP
• Swarovski EL
• Swarovski SLC 8x30
• Zeiss Conquest
• Zeiss Victory FL

Mid Size Binoculars

Alpen Apex 8x32

Alpen has packaged this binocular nicely in attractive dark green rubber armoring and given it tethered objective lens covers and twist-up eyecups. Although its resolution and brightness are not exceptional, this binocular does focus as close as 4 feet. Our glasses-wearing judges found the eye relief (16mm) somewhat inadequate, but it is comfortable for someone who does not wear glasses.

Brunton Eterna

It focuses as close as 4 feet, closer than your eyes can converge through the two barrels of the binocular. And although you won't be using the binoculars to look at a bird that close through both eyes, at least you won't have to back away if you see something up close you want to magnify.

What makes it stand out is its carrying case, which the manufacturer calls the "BinoGlove™ neoprene protective case." It's built for the binocular to wear while in use. It's a spongy (and somewhat bulky) wrap with Velcro fasteners that open to allow access to fingers and eyes. It may seem cumbersome and overprotective, but it could be useful for rock climbing or other extreme conditions. These binoculars feel as if they will stand up to use in rough conditions.

Even out of the case, the binocular is protected by nonslip rubber armoring. The lens covers attach with hinges. The eyepiece covers rotate and can be used to deflect the sun from getting in the user's eyes. The eye relief of 16mm in the 8x32 may work for some glasses wearers, though our glasses-wearing judges found their field of view somewhat restricted. Eye relief (15mm) in the 10x32 cannot be recommended for most glasses wearers. Both the full-sized and the compact models of the Eterna have longer eye relief than the mid-sized models.

Celestron Noble 8x32

If wearing glasses has kept you from using mid-sized binoculars, you might want to try this offering from Celestron. The manufacturer lists the eye relief as 20mm. And when we tried it in our tests the judges who wore glasses reported that they saw the most complete field of view with this binocular of any mid-sized binocular we tested.

The Noble has twist-up, click-lock eyecups and a compact shape. It focuses close (5 feet). The focus knob is particularly smooth and easy to turn, making for a relatively quick transition from close to distant viewing. The optical quality is good, and the price is moderate. This was a favorite of our judges. A good value.

Eagle Optics Ranger

Wow! Look at your socks! (Or if you have long thighs, look at your knees.) Okay, so you can't converge the barrels on a target that close. It's still a lot of fun to magnify near objects like that, even with just one eye open. Besides the tour de force of a 3-foot close focus, the 32mm Ranger has a focus knob that's smooth and fast to turn. Although the stated eye relief is 16mm, our judges who wore glasses found their field of view somewhat restricted. On the other hand, comparing the Ranger side by side with much higher-priced mid-sized binoculars, our judges found the difference in brightness and resolution relatively small.

Leica Trinovid BN 8x32

Leica is still making and selling its Trinovid binoculars. Even though the new Ultravid is available, the Trinovid still gets a lot of respect for its sublimely bright and clear optical quality. Our judges especially liked the 8x32 mid-sized Trinovid. Its close focus of 7.2 feet is not shabby. At 22 ounces, it's a manageable weight, but some of our judges complained about its hard exterior. Eye relief is 15mm.

Leica Ultravid 10x32

Leica managed to get a preproduction example of the new 10x32mm Ultravid to us on the day before our deadline, long after our team testing day. We're glad we got to see it. It's one of the smallest, lightest-weight mid-sized binoculars we handled. Of course, the optics are superb. The focus knob is silky smooth. It has the same elegant, easy-to-use diopter adjustment and click-lock, twist-up eyecups as the full-sized Ultravid. It focuses down to about 6 feet.

If it had been blessed with longer eye relief, it would have been a great favorite. However, its 13.5mm eye relief makes it unsuitable for most wearers of glasses. It comes in 8x32 and 10x32. The example we saw was a 10x32.

Leupold Wind River - Katmai 10x32

Honors for shortest binocular in our survey go to the 4-inch Leupold Wind River. Its eyecups twist up with positive-click stops to help in choosing the right degree of eye relief. Although the Wind River had the narrowest field of view (334 feet) of all the 8x32s we looked at, the 4.9-foot close focus and compact shape may make this a suitable choice for a person who wants to be ready for butterfly watching without having to carry a large binocular. Its eye relief is 16mm.

Minox BD 8x32

In the tests, most of our judges liked the 32mm Minox, although two of them mentioned that the focus knob was hard to turn and the central hinge a bit stiff. The Minox focuses down to 5 feet, which is about the minimum distance at which both eyes can converge through binoculars. At that close range, to get both eyes looking at the same thing one has to nudge the two barrels a bit closer together than normal and slightly over-converge one's eyes. Then, in the sliver of overlap between the two barrels, the supernaturally magnified object looks realer than real.

The mid-sized Minox comes in 8x32 and 10x32. We looked at the 8x32. It's less than 5 inches long and weighs only 21.7 ounces. It actually has a wider field of view than the full-sized 8.5x42 Minox.

Nikon Premier LX 8x32

Replacing the Venturer LX, the new Nikon Premier LX has all the good characteristics of its time-tested predecessor. Nikon now builds its top-of-the-line binocular with a magnesium-alloy body that takes several ounces of weight off the shoulders, but the Premier is still somewhat larger and heavier than other mid-sized binoculars.

The new Premier 8x32 weighs 28 ounces, and the 10x32 is 27.8 ounces.

Like the Venturer before it, the Premier LX is outstandingly sharp and bright, with excellent contrast. The eye relief (listed at 16mm) seemed better than most. It comes in 8x32 and 10x32.

We looked at the 8x32.

Pentax DCF XP

With this close- and-fast-focusing binocular you can zip with one motion of your index finger from looking at your own shoelaces to zeroing in on a hawk circling against the clouds. The Pentax DCF XP weighs a mere 17.6 ounces. Two of our judges remarked that it perfectly fit their hands and was

a pleasure to hold. It has tethered objective lens covers that won't get lost.

Optically, we found it pretty good. Although it tested slightly less sharp than the full-sized Pentax DCF HRII and the Pentax DCF SP, its resolution did not disappoint when used without close comparison to its full-sized relatives.

The narrowness of the field of view bothered several of our judges. In the 10x33 model, it provides a field only 279 feet wide at 1,000 yards-the narrowest field of view of any 10x binocular in the mid-sized survey. The 8x33 was the second narrowest (342 feet) among the 8x binoculars. Nevertheless, it's a moderately priced, lightweight, remarkably compact binocular for birding and butterfly watching.

Swarovski EL

We loved getting our hands on the 32mm Swarovski EL binocular. It's a pleasure to slip one hand around a slender barrel and pick up and focus the binocular, leaving the other hand free. On the mid-sized 32mm ELs, Swarovski includes all the details we loved on its full-sized siblings, such as tethered lens covers and a smoothly turning focus knob.

Optically, the 32mm ELs continue Swarovski's tradition of excellence, giving a satisfyingly sharp, high-contrast image. They focus down to 7 feet. The field of view is even wider than that of the full-sized 42mm ELs (at 1,000 yards, 360 feet in the 10x32 and 420 feet in the 8x32). In a welcome improvement, Swarovski has re-geared the focus mechanism on all of the EL series to speed up the rate of focus.

Unfortunately, the 10x32s have only 12mm of eye relief, providing a significantly restricted field of view for people who wear glasses. Eye relief of 15mm in the 8x32 is minimally adequate for many glasses wearers. The 32mm Swarovski ELs are available in 8x32 and 10x32.

Swarovski SLC 8x30

The Swarovski SLCs have been around for a few years and they remain in high regard among birders, even though Swarovski has since brought out the closer-focusing EL line. Most of the SLC's are heavier than the comparable ELs, but this smallest (8x30) SLC weighs just 20.8 ounces, an ounce under the EL 8x32. Our judges loved this binocular, which we found as bright as any binocular in the survey. The optics are superb-sharp, with great contrast and with no chromatic aberration.

It doesn't focus quite as close (13 feet) as the Swarovski 8x32 EL (which focuses at 7 feet), and it doesn't have the EL's hollow bridge. On the other hand, it costs only two-thirds as much as its sibling competitor. The eye relief of 15mm is the same as that of the Swarovski EL 8x32.

An oddity of the 8x30 SLC is the focus knob's placement at the far end of the central shaft. One of our judges found it difficult to find with his little finger. However, many birders like being able to focus with the pinkie or ring finger, leaving the index and middle fingers free to stabilize the binoculars. One person on our panel declared it "a little jewel."

Zeiss Conquest

When you first pick up the mid-sized Conquest, you notice that it feels lighter than you expect it to. At 15.9 or 16.4 ounces, the Conquests were the lightest-weight binoculars we tested. Zeiss employed its weight-trimming techniques in the lenses, while maintaining good optical quality.

Both models focus down to 9.8 feet. We found the focus knob somewhat stiff. The eye relief seems only marginally adequate for most glasses wearers, and the field of view less generous than most of the binoculars in the survey. However, it is optically sharp and bright. Its price is one-third that of Zeiss's top-line Victory FLs. 8x30.

Zeiss 32 Victory FL

By the time you read this article the new 32mm Victory FLs should be available. Zeiss plans to introduce them in late December 2004 or January 2005. We got a chance to see a preproduction 8x32 at the last possible moment before our deadline. We loved the binocular. It has the usual assortment of virtues-black rubber armoring, twist-lock eyecups, 6.6-foot close focus. It's a pleasure to look at the bright, clear, true-color image it provides.

But the icing on the cake is the wonderful eye relief. It actually allows the glasses wearer-even a glasses wearer whose glasses do not fit closely-to see the full picture. It looked like 100 percent to us! And yet the field of view is one of the most generous we saw. Zeiss especially designed an eyepiece with the characteristics that glasses wearers ask for, and they did it on a binocular of impeccable optical quality. Bravo!

The 32 Victory EL will be available in 8x32 and 10x32. We saw only the 8x32.

Definitions

Exit Pupil

The column of light coming through the binocular and into the eye is known as the exit pupil. The diameter of the exit pupil is determined by a simple formula. Divide the diameter of the objective lens by the magnification. If the binocular is an 8x32, the exit pupil is 4mm. (32mm / 8 = 4mm).

Increasing the size of the objective lens increases the size of the exit pupil. (An 8x42 has a bigger exit pupil than an 8x32.) But increasing the magnification decreases the size of the exit pupil. (A 10x32 has a smaller exit pupil than an 8x32.)

For maximum brightness, one needs for the binocular's exit pupil to be as big as the eye's pupil. If the exit pupil of the binocular is smaller than the pupil of the eye, then the image will appear dim.

If the pupil of your eye is smaller than the exit pupil of the binocular, some of the light won't get into your eye, and you won't get the benefit of it. Light enters the eye only through the pupil of the eye. Having an even larger exit pupil wouldn't make the image any brighter.

Close Focus

All good binoculars focus easily on distant objects. But they vary in their ability to focus on what is close at hand. In response to the demands of birders and butterfly watchers, manufacturers have developed binoculars that focus much closer than the binoculars of a few years ago. Among the 102 binoculars studied for this series of reviews, nearly three quarters of them focused within 10 feet.

However, the close focus statistics provided by the manufacturers are only guidelines. Close focus varies from person to person when they're looking through binoculars, just as it does with the naked eye. In general, a younger person can focus a little closer through the same binocular than an older one can. To determine true close focus, you have to try the binoculars with your own eyes.