follow us on twitter, facebook, pinterest, youtube, foursquare and google+

 “where cheap is chic” — wisebread

Home » Fitness & Sports » Binoculars » Binocular Magnification

Binocular Magnification, Focus

Related Guides: Hiking Backpacks, Hiking Boots and Sleeping Bags

The primary features of cheap binoculars are the magnification and objective lens width. Binocular magnification refers to how much larger the distant object will appear, or how much closer it will seem to you.

The greater the binocular magnification, the more light is needed to display the image on the binocular lenses, which in turn requires a larger objective lens. The objective lens width is the width of each of the two lenses on the binoculars. The greater the lens width, the more light is collected; the more light, the brighter the image appears.

The binocular magnification and lens width are typically included in the model name. For example, Bushnell Permafocus 7x35 binoculars have a magnification of 7x, which means objects will appear seven times closer than they actually are, and an objective lens width of 35mm. For most outdoor activities, such as bird-watching or sightseeing, a 7x or 8x binocular magnification is appropriate. All three of our top picks boast one or the other of these binocular magnifications. The Vivitar CV-1025V 10x25 provides a magnification of 10x, a level that rewards viewers with a bit more detail than 7x or 8x but somewhat crimps their field of view (see below).

For indoor activities such as opera or theater, a lower binocular magnification (such as 3x or 4x) is often preferable because the lower magnification requires less light to magnify the image. For example, the LaScala Optics Othello 3x25 Opera Glasses (starting at $30, Amazon) are designed for the dim light of theater and opera performances.

Some binoculars, like the Barska Gladiator 7-21x40 Zoom (starting at $30, Amazon), can change magnifications with a zoom lens so you can choose the correct binocular magnification for any situation. In this example, magnification starts at 7x and reaches up to 21x, but the flexibility doesn't impress users. Reviews of this model posted at Amazon report an inability to bring the view into focus, with serious problems arising at magnification as low as 10x. Note, though, that models with variable magnification in general perform better at lower magnification levels than at higher levels.

Binoculars Field of View.

A binocular's field of view determines how much surface area you can see in the distance. Let's say you're looking at a bird 1,000 feet away. A larger field of view lets you see more of the area around the bird, making it easier to follow as it moves on the ground or flies through the air. Similarly, if you're watching an opera performance or a football game, a larger field of view lets you see more of the stage or the playing field.

The field of view is determined in part by the objective lens width but also by the design of the lenses. You have a wider field of view with lower binocular magnification than with higher binocular magnification. Again, this is where your intended use should help guide your purchase decision. For birders, experts at Optics Planet caution against giving priority to a wide field of view because you could be sacrificing image clarity. Enthusiasts of team sports, on the other hand, may rank a wide field of view above ultra-sharp detail on their list of priorities.

Field of view is measured in the number of feet around a center point that you can see at 1,000 yards. For example, the Bushnell Permafocus has a very large field of view: 578 feet at 1,000 yards. Our two other picks, the Olympus 8x21 Roamer DPC I and Bushnell Powerview 8x21, respectively feature a 336-foot and 378-foot field of view, which is quite respectable. The Vivitar CV-1025V 10x25 is graced with a narrower 303-foot field of view.

Binoculars Focus Adjustments.

Most binoculars typically have a center focus knob and some kind of diopter adjustment. The center focus knob lets you zoom in on an object or scene, while the diopter adjustment lets you adjust the strength of the right and left ocular lens to compensate for the strength or weakness of each eye. Most cheap binoculars we researched feature a central focus knob, and the Olympus 8x21 DPC I boasts a built-in dioptric adjustment as well.

One notable exception is the Bushnell Permafocus 7x35. These cheap binoculars are designed for someone who just wants to lift the binoculars to their eyes and look at something in the distance. To keep things simple, the focus on this model is permanently set to infinity. This means that everything farther than about 50 feet away will come into clear focus. While this type of focus is not suitable for up-close viewing, it's ideal for anything with a lot of action, like a horse race or ball game.

by Elizabeth Sheer (Google+ Profile)

Back to top »

 

 

 

Barska Gladiator 7-21x40 Review
LaScala Optics Othello 3x25 Opera Glasses Review
Vivitar CV-1025V 10x25 Binocular Digital Camera Review
Bushnell Powerview 8x21 Review
Bushnell Permafocus 7x35 Review
Olympus Roamer 8x21 Review

Nikon Action 7x35
Bushnell H20 Porro Prism 8x26 Waterproof Compact
Bushnell Powerview 8x21
Eagle Optics Energy 8x21
Vivitar 1502612 4x30
Eagle Optics Triumph 8x25
Olympus Outback 8x21 RC I
Bushnell Permafocus 8x25
Pentax Papilio 8.5x21

 

Fitness & Sports Snowboard Bindings Bicycle Helmets Bike Locks Binoculars Ellipticals Exercise Bikes Hiking Backpacks

Hiking Boots Mountain Bikes Sleeping Bags Snowboard Boots Snowboards Tents

Treadmills Walking Shoes Workout DVDs Yoga Clothes Yoga Mats Running Shoes

blog  about us  contact us  sitemap  in the news  privacy  terms of service  jobs

Follow us on Facebook Twitter Sign up for our Free Newsletter