Binoculars

The short answer is: it depends. That is to say, it depends on what you're planning on using them for. Concerts or sporting events? Bird watching? Stargazing? Travel? Each different use might require slightly different features. But, there are some basics that you should consider.

The Basics: A Definite Eye Opener

The first thing you'll want to consider are the numbers associated with binoculars such as 7x35 or 8x42. The first number represents the magnification, which is how many times closer your subject is to you. While you might be tempted to buy binoculars with the highest magnification possible it can make image shake more noticeable, give you a smaller field of view, and make it difficult to find subjects or track moving objects.

The second number measures (in millimetres) the diameter of the front or objective lens and determines how bright your image will be. The larger objective lenses let in more light giving you a brighter image. Larger lenses means heavier optics so you'll definitely want to take that into consideration when making your purchase.

While weight may or may not, factor in deciding what binoculars are right for you, you might also want to consider the size and shape. Binoculars generally come in 2 basic shapes based on the type of prism they have. Porro-prism binoculars have the classic binocular shape with the front lenses offset from the eyepieces creating an angled light path. Roof-prism binoculars have a straight-barrel light path and tend to be smaller and more compact than porro-prism binoculars.

Last but certainly not least, keep in mind the field of view (FOV). It's the width of the entire image you're viewing seen through the optics focused on an object 1,000 yards away. A wide FOV, makes it easier to find and track objects. FOV can be expressed in 2 different ways width at distance or in degrees.

Of course, getting the right pair of binoculars will depend on what you're using them for.

Bird/Nature Watching

Looking to do some bird or nature watching? You'll want to have a modest amount 7x or 8x. Higher magnification might be nice, but you'll have a smaller field of view. Of course, large objective lenses will give you a bright, high resolution image. Just remember to consider the weight of your binoculars if you're going to be viewing wildlife for an extended period. For large magnification and/or large objective lenses you might want to consider using a tripod.

Concert/Theatre/Sporting Events

For indoor sporting events, concerts, or the theatre consider a compact, lightweight pair of binoculars with magnification of 4x to 8x. Lower magnification will let you see a wider area and for sports so you can track motion easier. Some indoor events such as concerts and theatre performances can be fairly dark so consider binoculars with larger objective lenses. You may also want to consider zoom binoculars so you can zoom in on subjects to get more detail.

Stargazing

High performance optics are a must for stargazing. Consider binoculars with large objective lenses, 40mm to 50mm. And because of the large front lenses you'll definitely want to consider a tripod to stabilize the binoculars so you have a better image that's free from shaky hands. Using a tripod will also give you the option choose a pair of binoculars with a higher magnification.

Travel/Outdoors

Portability will be your biggest consideration so a lightweight and compact design is a must for travel, something that you can keep in your pocket or easily take out of your bag. Depending on the type of outdoor excursions you like taking also consider getting water-, fog-, and/or impact-proof binoculars. Zoom binoculars could be useful for travel and outdoors viewing as well, so keep that in mind when you're looking to make your purchase.

General Purpose

A good general purpose pair of binoculars would be a 7x35 or 8x42 since they should be portable and have a good FOV so you have a good image and can easily track moving objects. As with anything though, pick the pair that's best suited to your needs and your budget.