Optics

Quality is another factor, but all of the models I sell can be considered mid-range; they are good, general purpose binoculars that will withstand years of moderate use. They have fully-coated lenses, which makes them more resistant to scratches from dust and other particles. They will not give you the highest image quality available (you can pay hundreds of dollars for that), nor are they specially designed for low-light conditions, nor heavily armored for rough handling. If you use binoculars professionally and need them for many hours daily, I recommend you invest in something more costly than what I have to offer. But if you want a pair for weekend birding, sporting events, vacations, and other moderate uses, these are a good buy.

This is fairly easy to understand, a binocular of 10 power makes the object you are viewing look 10 times bigger. A 7 power binocular makes objects look 7 times bigger. So why, you may wonder, does not everyone just choose the most powerful binocular they can afford? More powerful is better, right?

Not necessarily. There are two other things to consider. First, the more powerful binoculars usually have a lesser "field of view" than those that give you less magnification. Field of view is how wide an area you can see, and this is very important if you are trying to spot moving objects, such as birds, airplanes, or football players. It is much easier to zero in on your subject before it's gone if you have a larger field of view.

Second, the more powerful the binocular, the more visible is the tremor in your hands. If you get much above 8 power, most people won't be able to hold the binoculars steady enough. This is not important if the intended use enables you to brace the binoculars against, say, a fence, or your knees, but is very important if you are doing your viewing from an unsupported standing position. When the image jumps around because of hand tremor, you lose the advantage of the greater power.

In listings for binoculars, you'll see two numbers, 7 x 50, for example, or 8 x 22. The first number is the magnification. The second is the size of the larger ("objective") lenses, in millimeters. The size of these lenses is important for image quality because larger lenses let in more light and thus are more useful in low-light conditions; also they can give you maximum field of view without resorting to the greater image distortion that a wide-angle lens gives you. The only real disadvantages to binoculars with larger lenses is that they are heavier—an important consideration unless you have a neck like a mule—and that they are larger. You're not going to be able to carry a 7 x 50 in your shirt pocket!

Field of view is expressed in either of two ways: In degrees, or in the width of the image at a specified distance. If you look around in a complete circle, you have just viewed 360 degrees, so the 5 to 9 degree view you get with most binoculars is just a small portion of that field. The width of the image you view is usually (in this country) expressed in terms of the number of feet you see at a distance of 1000 yards, 357 feet at 1000 yards, for example. Note that the wider the field of view, the more likely you'll be able to locate a moving subject: A bird flitting around in a tree, a jet flying across the sky, a soccer player running down the field. So why not have the maximum field of view possible? Because the greater the field of view the more distortion of the image you get; the larger, "objective" lenses have to curve more to capture the wider view and this distorts things more.

The size of the binoculars may determine whether you actually use them very much. The larger binoculars are great: They give you a clearer image, are better in low-light conditions, may have a relatively larger field of view. But if you intend to take them along on hiking trips or long walks, you may find the extra weight rather irritating. After a few outings with heavy binoculars hanging around your neck all day, you may think twice about bringing them along. And the trip you leave them home may be the one where the condor or bald eagle passes lazily overhead, or the cougar steps out of the woods a hundred yards away!

So this is where the compacts are sooooo nice. You can clip them on a belt or put them in a coat pocket and you'll get so much more use out of them for hikes. Save the larger models for chairside bird watching or sports stadium viewing.

A good general use binoculars for conditions when you don't mind the 1.75 pound weight. 50 mm objective lenses give you a bright image and a 6.8 degree field of view (=357 feet at 1000 yards). Eyecups roll back so that those of us who wear glasses can have our eyes positioned at the proper focal distance. Comes with a padded cloth carrying case. The image at left shows a very similar model in the same Enduro series.

Compact enough to fit in a coat pocket, at 13 oz. (including pouch), light enough to not be too bothersome hanging from your belt. Gives you 5.2 degrees field of view (=273 feet at 1000 yards). Rollback eye cups for wearers of glasses. This magnification is not recommended for those who cannot keep a steady hand when viewing. Comes with a durable vinyl belt pouch.

Here is a variety of magnifiers for botany, entomology, geology, gemology, philately, and just plain reading. We get all of our stock from Donegan Optical, a Kansas manufacturer of quality visual aids.

Website for US and limited international deliveries only.

Vantage 23 mm 10x Coddington Hand Lens

This lens is pictured at left in the image above. The 23 mm (approximately 7/8 inch) lens is wider than most commonly available hand lenses, giving you a broader field of view. The 10 power magnification enables an in-depth view of flower structures or details of insect anatomy or minerals. Weighs about 1-1/3 ounces with glass lenses mounted in what appears to be a milled aluminum case, which will resist corrosion. Folds to help protect the lenses. Imported from Japan.

Item #960. Shipping weight: 0.1 lb. Your price: $13.00

Choose shipping speed

How to Order

Vantage 15 mm 10x Coddington Hand Lens

Illustrated in image above at right, the smaller lens. Similar construction to the 23 mm, but lens only 15 mm across. Also with 10 power magnification. Weighs less than an ounce. Imported from Japan.

Item #959. Shipping weight: 0.1 lb. Your price: $8.50

Choose shipping speed

How to Order

The three 30 mm wide lenses in this magnifier can be used in combination or separately for a variety of magnifications. It also has the largest field of view of any 10- or 15-power hand lens we sell. Like the others, the lenses are folded back into the case when not in use. The case and lens mountings are a tough black plastic. Case measures about 1¾ inches long. Image at left shows one with lenses folded, the other with lenses out.

Having multiple magnification levels is an advantage in that sometimes you need the broader view you get at lower magnification, and sometimes you need the best magnification you can get. The down side is that with two extra lenses, you have four extra surfaces to pick up dust and lint, so you will need to spend a bit more time cleaning lenses than the others.

Coated lens eliminates minor color distortions experienced with cheaper models. Mounted in a chrome-plated brass case, which, like the other hand lenses here, serves as a handle when in the open position. A vinyl snap-close case is included. Looks almost identical to the 20x model shown below.

Like the 15 power model above, but with 20 power magnification. Why would you not want to get the strongest lens when it is just 25 cents more? Because the higher magnification has less field of view—you can’t see as wide an area—and you also need to get closer to your subject with higher magnification. In field conditions, this means that you are often casting a shadow on your subject when you are that close. On the other hand, you can see more detail, and if that’s what you need, go for 20 power!

Two lenses which swing out from one case (which serves as a handle). The larger lens gives you 15 power for great detail and relatively large field of view. When you need even more detail, the smaller 20 power lens will do the trick. Mounted in chrome-plated brass case. Vinyl snap-close storage case included. Image at right shows a side-view of the same lens, with the 20x lens folded inside the handle. Imported from Japan.

To effectively use any of the lenses above or the Magni-Pak lenses below, you must hold the lens close to your eye, and the subject you wish to view close to your lens. Beginners usually make the mistake of holding the lens several feet away from their eye; this gives them both less magnification and less field of view. The exact position you need to adopt depends on your visual acuity and your eyeglasses (if any). But for me, when I'm wearing glasses, the lens of the magnifier rests against my eyeglass lens, and I hold the subject less than an inch away. If I use the hand lens when not wearing glasses (I'm near-sighted), the lens just about brushes against my eyelashes, and the subject is about an inch away from the lens here, too.

This magnifier, illustrated at lower left in the image above, folds into its own case (as in the blue inset) for protection. The 4 cm diameter lens gives you a wider field of view than the Coddington hand lenses described above, and its overall larger size makes it easier to handle for kids. Like the Coddingtons, it is best used with the lens held close to your eye—but because of the wider lens, you can hold it at a greater distance from your eye and still find it useful.

This instrument is like the 5x, except it has two lenses (image is upper right). You can use the lenses separately to view objects at 4x magnification or 5x magnification, or you can combine them for 9x power.

Index to the Mindbird Maps & Books website, www.mindbird.com
Globes	Map Accessories	Books	Optics	Rite in the Rain	Grand Canyon National Park
US Road & Street Maps	US State Wall Maps	US Wall Maps	North American Park & Forest Maps	International Maps	World Maps
USGS Topo Maps	Geologic Maps	Bandana Maps	Map Games	Historic Maps	Maps of Continents
Raised Relief Maps	Stars & Planets			How to Order	Contact Us

Original content copyright © Lee Dittmann of Mindbird Maps & Books.
Images may be copyright © by the creator of the items depicted.
Essential ordering details, including phone, fax, mail, and online options, shipping fees and delivery times, returns, special orders, privacy policy, and more are described on the How to Order page.