Cheesemans' Ecology Safaris

About Binoculars

Background

A good binocular can really enhance your safari experience and is a very valuable tool when viewing wildlife. For some tours, they are indispensable such as to our neo-tropical destinations in Central and South America. These are places where you may be seeking birds and mammals high in the dark rainforest canopy. At other destinations, a binocular may not be as important, for instance on our Antarctic trips where the wildlife is close (however, binoculars become very important when searching for and viewing wildlife at sea).

There’s a lot to know about binoculars and understanding their features will aid you in purchasing the binocular that fits your needs.

What are binocular features?

 

Magnification

Binoculars are referenced by a set of numbers such as 8×42 or 10×50. The first number (8 and 10 in our example) is the magnification or how many times closer the object appears through binoculars compared to the unaided eye; a higher number means more magnification. This is a fixed number on a binocular and typically can range from 6 to 15. There are advantages and disadvantages to higher magnifications though. All other features being equal, a higher magnification binocular will deliver a smaller field of view, less light, and are more difficult to hold steady but will bring the wildlife “closer” so you can see more details. A lower magnification binocular will deliver a wider field of view and a brighter image and will be easier to hold steady but the observed object won’t be as “close” as with a higher magnification binocular.

Objective Lens

The second number (42 and 50 in our example) is the size of the objective lens. The objective lens is the one furthest from your eyes or closer to the object being viewed. The objective lens gathers the light, so a larger objective lens gathers more light and potentially delivers it to your eyes. The disadvantage to a larger objective lens is that it makes the binocular larger and heavier.

Field of View

The field of view is how many feet across you can see from left to right at a distance of one thousand yards. It is specified in distance (feet) or angle of view (degrees). (Note: if you want to convert degrees to feet at a thousand yards, multiply the angle by 52.5 feet). Field of view is important especially when viewing wildlife that moves around a lot. It is easier to track moving wildlife when your field of view is wider. Plus it is easier to initially locate the wildlife when you have a wider field of view.

Minimum focusing distance

Some binoculars allow the user to bring very close objects into perfect focus – typically the closest range is about four to five feet but some will focus as close as three feet. These binoculars are great for looking at butterflies, hummingbirds, penguins, and other close wildlife. However, if your eyes aren’t able to see a single clear image when focusing on close objects, don’t force your eyes to merge the images, as this will damage your eyes. In this case, either close one eye or don’t look through the binocular. The bottom line is that the further the distance between your eyes, the better your chances are of using close focusing binoculars.

Speed of focus

Some binoculars allow you to go from focusing at a great distance to focusing up close in less than one revolution of the focus wheel. This is beneficial if you are viewing wildlife at all distances. However, as with getting used to driving a Maserati compared to a Kia, you have to get used to turning the wheel less to focus.

Weight

Binoculars designed for field observation can range from 11 oz. up to about 35 oz. The weight is dependent on the size of the objective lens (see Objective Lens) but keep in mind that higher quality lenses are generally heavier. Before you purchase binoculars, handle and test them in the store to make sure the weight is comfortable especially if you will use your binoculars for extended periods of time.

Waterproof and Fog-proof

A top quality binocular is filled with nitrogen gas (nitrogen purged) that makes it waterproof and fog-proof – this is critical in tropical or cold conditions. Keep in mind that fog-proof means only that the internal lens surfaces won’t fog; the external surfaces can still fog. This is a critical feature since when internal lenses fog they become useless only delivering a dingy gray image. External fog may happen but it can easily be wiped off with a micro-fiber lens cleaning cloth.

Durablility

Most good binoculars are also “armor” coated or “rubberized”. This means they can survive normal knocks and scrapes without causing alignment or structural problems.

Coatings

Binoculars are composed of multiple lenses. Light can disperse or scatter at each lens surface. To combat this problem, lenses are covered in non-reflective coatings that allow the light to pass through more efficiently. The best binoculars are fully multi-coated which means that several layers of coatings are applied to each lens. Efficient passage of light (or less dispersal of light) means that more light is passed to your eye resulting in a brighter image. This is important very under low light conditions such as in forests or on cloudy days.

How do I use binoculars?

 

Eyecups

It’s critical that you know how to use eyecups since they fix the distance between your eyes and the lens. If there is too much distance between your eyes and the lens, the field of view will be smaller and you’ll have more difficulty locating the object. If there is too little distance between your eyes and the lens, you’ll see alternating dark shadows that are very annoying. Your eyeballs need to be about an inch from the ocular lens (the lens closest to your eyes) of the binocular to maximize your field of view. Eyecups can be used or “stowed” – generally, stow the eyecups if you wear eyeglasses since your eyeglasses will give you the one inch distance. Stowing methods can be either folding down, pushing in or out, or twisting in or out. The method employed high-end binoculars is usually twist up and down with locking at different distances.

Interpupillary Distance

For binoculars, this is the distance between the centers of the ocular lenses (the lenses closest to your eyes) measured in millimeters. To use binoculars effectively, this distance must match the distance between the centers of your pupils. You can adjust the binocular’s interpupillary distance by spreading the two lens barrels apart or moving them closer to match your eyes. If your eyes are particularly close set or far apart, make sure you can adjust the interpupillary distance to match your eyes before you purchase. If the interpupillary distance can’t be adjusted to match your eyes then it doesn’t matter how wonderful the binocular is – you shouldn’t use them because you run the risk of forcing your eyes, which could damage them.

What binocular should I purchase?

 

Search your soul

Binocular quality and price vary a great deal and a little research will help you buy exactly what you need. It is very important to do some soul searching to decide what you will use them for. If you only want to bring them to concerts or sporting events, then you only need an inexpensive compact binocular that you can throw in your pocket. If you will be using them to view wildlife on a Cheesemans’ Ecology Safaris tour, then durable, high quality binoculars are best.

Cost

Generally prices range from $300 to $2,000. Even though spending over $1,000 on binoculars may seem daunting, it is worth the higher price especially if you use them often. Keep in mind that higher quality binoculars will truly enhance your wildlife viewing experience. Also, its best to purchase the highest quality that you can afford instead of purchasing a new pair each year because you out-grew the quality of the last pair.

Recommendations

The most important thing before you purchase is to determine what you will use them for before you purchase! There are many very good high quality binoculars on the market today. It behooves you to handle and look through a variety of binoculars. We also recommend purchasing from a “brick and mortar” store so you can test before purchasing or, at the least, purchasing from an online re-seller who will ship you a binocular to preview before you purchase.

We also recommend that you use a suspender harness binocular strap (see examples) since they take the pressure off the back of your neck and are especially good for carrying heavier binoculars all day in the field.