Buying Binoculars: The Choice is Clear

Vintage BinocularsBinoculars are perhaps some of the most popular and useful optical instruments that are used for a variety of different purposes. Different types of binoculars are available depending on your activity, coming at various price points.

Novices will look at all the binoculars and say they all look the same – but each pair has its own specialty, depth of application, and quality. Binoculars and optics are one of the few types of products where quality is paramount, and to get the best binoculars for the money, you will truly get what you pay for. This makes it necessary to understand the basic specifications of a pair of binoculars, which will help you choose the right pair for your specific need.

Understand the Specifications


Binoculars are designated with two numbers separated by an X. For example: an 8×42 pair or an 10×50 pair. The first number of this designation is known as magnification or the power of the binoculars. A 10x pair means that the object you view through the binoculars will be optically magnified 10 times that of the naked eye.

However, it is important to note here that higher magnifications do not represent a better pair, the best magnification depends on the application of use. Very high magnification lenses come with certain drawbacks – shaky images due to hand movements, narrow field of view and darker images.

Objective Lens

The second number in the designation is the diameter of the objective lens. An objective lens is the outermost lens in a pair of binoculars, which gathers incoming light. The diameter of the objective lens represents the light collecting power of the lens. For a given magnification, a higher objective lens diameter means greater light collecting power and thus brighter and higher resolution images. However, a larger objective lens means a heavier pair of binoculars.

Field of View

The field of view of binoculars is the total visible width at a distance of 1000 feet or meters. The field of view determines the area of visibility through a pair. The greater the field of view, greater is the end to end width of visibility. The field of view is related to the magnification – higher the magnification, lower is the field of view and vice versa.

Exit Pupil

The exit pupil represents the size of the light circle at the eye piece of the binoculars. Standard exit pupil sizes are calculated by dividing the objective lens diameter of a pair by its magnification – a 7×21 pair will have an exit pupil of 3mm. The bigger the exit pupil, the brighter is the image viewed.

Relative Brightness Factor

The relative brightness factor is a number that gives you a rough idea of the brightness of the image captured by the binoculars. Numerically, the RBF is the square of the Exit Pupil. Thus an exit pupil of 4mm represents an RBF of 16. The RBF does not factor in the various measures taken to increase brightness such as lens coatings; number of lenses used etc and is only a representative number.

Twilight Factor

The Twilight Factor is a relative number that describes viewing under low light conditions. Numerically, the twilight factor is the square root of the magnification multiplied by the objective. For example, 7×21 binoculars will have a twilight factor of 12. The higher the twilight factor, the better is the visibility in low light.


Binoculars have a pair of prisms that allow light to pass through them. Based on the orientation of the prisms, Binoculars are of two types – Porro and Roof (Dach). Porro prism binoculars are less expensive and offer a wider field of view. Roof prism binoculars are much smaller and sleeker than their Porro counterparts making them more compact.

Lens Coatings

Lens coatings are used to minimize reflections off the surfaces of lenses and increase the transmission of light. Usually all the faces of the lenses are coated to increase transmission. However, in some cheaper binoculars, only the outer faces might be coated. The best binoculars will have fully multi coated lenses to provide the sharpest, brightest image possible.

Lens coatings are of the following types:

  • Fully Multicoated – All faces have multiple layers of coating (3-5 layers)
  • Fully Coated – All faces have a single later of coating
  • Coated – One of more faces have a single layer of coating

Choose Binoculars Based on the Activity

While choosing a pair of binoculars, always remember the purpose of its use. Binoculars are used for a number of activities such as bird watching, hunting, sky watching, watching athletic competitions, and even for concerts. Each activity has its own special requirements in binoculars to get the best experience.

Higher magnification does not mean better binoculars. A lot of other factors such as objective lens diameter, field of view, brightness factor have to be taken into consideration. The larger the magnification, the lower is the field of view and stability of the images decreases. Choose binoculars with just enough magnification, a sufficient field of view and an objective lens diameter. Higher objective lens diameters lead to greater light collection – for better and brighter images.

Bird Watching

Bird Watching with Binoculars
photo credit: Birdwatching at Nestucca Bay NWR

8x binoculars are considered the best pair to buy for bird watching, as they offer the following advantages:

  • Offer a sufficiently wide field of view
  • Eye relief and sufficient magnification
  • Stable image without the use of a tripod

Bird watching requires constant binocular movement. Thus, having a very high magnification pair will restrict your motion, as you will be forced to use a tripod to get stable images. Also, the wider the field of view, the easier it gets to follow the bird.

Choose a pair of binoculars that offers a good field of view at 7x or 8x magnification. For viewing birds at reservoirs, 10x or 12x magnification binoculars with a tripod are the best choices.


When choosing binoculars for hunting, it is imperative that you choose optics with excellent low light performance. The prey is usually most active during dusk and dawn and these are the times you will have a good chance for a kill, which is why hunters usually prefer high objectives of around 42-50mm.

The magnification of the binoculars depends on the terrain that you are hunting in. For a terrain full of trees, you will do better with wider field view binoculars of around 7x or 8x. If you are hunting in an open terrain, larger magnification 10x binoculars are a good choice.

Sky Watching

Stargazing with Binoculars
photo credit: SR_stargazers enjoying the view

Sky watching or stargazing requires different binoculars depending on what you intend to view. For example if you want to see the moon, even normal compact binoculars will be able to show you the surface clearly. For viewing planets like Jupiter and Saturn, a minimum of 10x magnification is required.

For night sky viewing, the greater the size of the objective the better. Since the night sky is very dimly lit, you need your binoculars to gather all the light it can for better viewing. Binoculars with objectives of 50mm to 80mm are generally picked.

Top Binocular Brands

Bushnell – Binoculars are at the core of the Bushnell’s outdoor product offerings. Bushnell has carved its name, as a top-rated optics brand for outdoor activities and has a range of binoculars for all activities –spectator sports, nature trails, sky watching and hunting. From the Powerview, their least expensive offering to the Legend Ultra HD binoculars, Bushnell has some of the finest binoculars in the market.

Nikon – Although Nikon is most famous for its digital camera products, their binoculars and other optical viewing products are some of the best in the market. Nikon founded a special sports optics division in 2001 to focus solely on binoculars and rangefinders. Nikon binoculars are a value for money – without compromising on quality. Their top range binoculars come with a 25-year warranty.

Vortex – Vortex Optics is an American family-owned binocular company with a focus on hunting binoculars and scopes. Their popular hunting binocular range includes the Vortex Razor, Vortex Viper, Crossfire and Fury. Vortex has recently come up with a bird-watching range of binoculars, named the Vortex Stokes Series.

Leupold – Leupold is an American family-owned binocular company with over 100 years in binocular optics. They are most famous for their Wind River binoculars that were introduced in 1994 and the Green Ring Series launched in 2001. The binoculars included in this series are the Cascade, Olympic, Yosemite, Mojave, and Pinnacles.

Leica – Although Leica Optics is best known for their range of microscopes, their binoculars are also very popular. Based in Germany, Leica Optics produces binoculars specifically for bird watching and hunting. While a tad expensive, the quality of the binoculars is second to none. Leica binoculars offer sharp images with good quality and color rendition. The company offers a no-fault lifetime warranty.

Steiner Optics – This German binoculars company is one of the most respected binocular brands in the industry. Their products are specifically built for military, marine and law enforcement uses – exhibiting high quality and industry leading designs. Their binoculars are nitrogen-filled to avoid lens fogging and are waterproof for up to 10 meters. What makes this brand exciting is the high quality German precision manufacturing going into each product. Some models are also used by the US Military.

Carl Zeiss – Carl Zeiss is one of the best brands in the world when it comes to lens designs. They have a range of lenses for every use – right from camera lenses to binoculars to riflescopes. Carl Zeiss binoculars edge towards the top end. Their innovation in binoculars is spectacular – from fluorine ion filled lenses to improve image quality to waterproof coatings and electronic glass display. Carl Zeiss manufactures binoculars in two ranges – the Victory range with top of the line features and the Conquest range, which has great quality but is more budget-friendly.

Vanguard Optics – Vanguard is a binocular manufacturing company from China. Although their name in the industry is not that well known, users swear by its quality. They manufacture both Porro and roof prism binoculars with the Endeavor at the top of their range. The Endeavor range features a special low dispersion glass, which is specifically designed for water sports and other marine applications.

Choosing Binoculars

Quality matters when buying optics, so you should now feel very confident in purchasing your investment either at the store or even online. Now that you understand the specs, you are ready to get the best binoculars for the money, for whichever activity you choose. If you have narrowed your binocular choice down to a price range, we have several articles that can help you choose the right model.

  • Top Binoculars $500 and Under
  • Top Binoculars $300 and Under
  • Top binoculars $200 and Under