Here is my guide to help you understand how to choose binoculars for your use.

Selection based on the use

The first thing that you need to define for yourself is the fact about the potential usage of these binoculars.

Decide if you need the binoculars for

Hunting

Bird watching

Kayaking/canoeing

Boating or Marine

Hiking

Astronomy

Spectator events

All purpose

This use in turn will determine the specifications of the binoculars that you need.

Here is the overview of the main features/specification of the binoculars.

Binocular Magnification or power of the binoculars

If you read the specification of any manufacturer for a pair of binoculars it has the first thing written as NxN for example 10×50 or 7×35. The first number is the magnification which means that how much closer you would be able to see the object. The second part of the equation is that objective lens diameter

Then there are zoom binoculars which have the option of a range of magnification for example 10-22×82 will mean that magnification can be varied from 10x to 22x .

Simple guideline for magnification is

Lower the magnification the more sharp and bright is the object and vice versa

Lower the magnification the more field of view or span you will be able to see and vice versa

Bigger is the objective lens diameter the more light it will receive.

Lens coatings and Image brightness

You will see these three or four shortened versions specified as FC, MC, FMC as the lens coating nomenclature. The coating on the lens means that the lens is coated with material it will increase the light transmission through the lens to your eyes.

Guideline

More light means brighter image

FC – fully coated – Single layer of magnesium fluoride

MC – Multi-coated – Some lenses are multi-coated

FMC – All lenses will be multi-coated.

Focus

Center focus and Individual piece focus

Center focus in binoculars has a single wheel with which you can focus the binoculars rather than having to focus each eyepiece In the Individual piece focus – Each eyepiece will have to be focused individually

Close focus

It is the distance at which the objects are very sharp when viewed thorough the binoculars.

 Field of view or FOV

This means the span of area that you can see from one end to the other through your binoculars at a distance of 1000 yards.

Guideline

Large the magnification the smaller is the FOV and vice versa.

For this reason only it is important that you know the use of the binoculars. For birding binoculars it is very important that you have a large FOV as you need to spot the birds in a larger area than you would do an animal in a hunting area.

Waterproof and Fogproof

If you are using the binoculars for outdoor purpose then it is always better to go in for waterproof binoculars especially hunting, birding or boating. If you are using the binoculars only for theater of general use then may be you do not need the waterproof binoculars.

Eye relief for people who wear eyeglasses

Very important feature that you should know if you wear sunglasses. The eye relief is a must if you wear eye glasses to see properly from the binoculars.

This is the distance between your eye and the eyepiece at which you can still see the entire span of the view or the filed of view. Needed for eyeglass wearing people as they will not be able to bring their eyes much closer to the eyepiece.

Digital camera Binoculars

As the name suggests these binoculars are those which have a digital camera also in-built along with the binoculars. You should know about the following things about the specifications of the digital camera binoculars

Internal memory capacity

SD memory card slot

Instant replay function – This will mean that it has to have a LCD screen

Exit Pupil

This is calculated as the objective lens diameter divided by the magnification and it will mean that a 10×50 bino will have 5 as exit pupil. This gives an indication if image sharpness and rightness

Guideline

A 2.5mm -3mm exit pupil is good during daylight

7mm is what a human eye can easily dilate to means an exit pupil of more than 7mm is not useful

Binocular design

Porro prism or the roof prism.

Porro prism are the older design of the binoculars and the roof prism is the more recent one. As far as viewing capability is concerned there is really no difference. The porro prism has more is more easy to manufacture and in general will cost less than the rood prism.

The rood prism is more compact and trendier.

Guideline

Roof prism binoculars are more rugged as well as more trendy but expensive to make.

Binocular accessories

Neck straps – A must for the ease of carrying as well as for the reason that it will prevent them from falling or you forgetting the binoculars somewhere unattended.

Tripod  - This is required if you are using the binoculars with large objective lens diameter normally above 50mm. Till 50 mm the binoculars you will get are relatively Ok to hold in hand but above that they become too heavy to be steady in your hand.

Always visit an offline store and make sure that you feel the binoculars in hand before making a decision about binoculars to buy. 

How to see the exit pupils of the Binoculars?

If you hold the pair of binoculars at an arm’s length then you will see a small circle of light in each the eyepiece. This circle which you see is the exit pupil. As a thumb rule the exit pupil diameter is the obtained by dividing the aperture in millimeters by the magnification.
For example, if the specification is 7×35 for the binoculars then the exit pupil of 5mm.

What does it mean to me if the exit pupil of a binocular is less or more?

The exit pupil of the binocular should match the entrance pupil of the human eye. In normal cases the human eyes’ entrance pupil for a young adult is 5-7mm.
This is important to know because generally that determines the image’s brightness.

If your entrance pupil diameter is less than the exit pupil diameter then outer edge of the small circle of light that is coming out of the exit pupil will fall on the sides of your entrance pupil and you will see a dimmer image.

In case your entrance pupil diameter is larger than the exit pupil diameter of the eyepiece then you will be able to get all the light and will see a brighter image.

That will mean that you should make sure that the entrance pupil of your eye is equal or more than the exit pupil diameter of the eyepiece.
Young adults have about 7mm diameter in low light conditions.  As you age the entrance pupil diameter will reduce.

What are the roof prism binoculars?

Roof prism binoculars have all the three things namely the eye piece, the objective lens and the prisms all in one straight line. This helped as then the design of the roof prism binoculars was more elegant and in general there would be no such thing as the zig-zag pattern of the Porro prism binoculars.

It is easier said than done. The design was more complex internally for the roof prism binoculars and hence it was tough to manufacture. That is why the low -end binos will always be those if Porro prism system and the high -end will be roof prism binoculars.

Roof prism binoculars vs. Porro prism binoculars

Roof prism binoculars are much better looking than the Porro prism binoculars as far the design is concerned.

On the price front the Porro prism binoculars are much better than the roof prism binoculars.

In terms of light efficiency the Porro prism binoculars are much better than the roof prism ones. However now with the phase-coatings being used on the prism glass the roof prism binoculars have become equally good compared to the Porro prism binoculars

Let us first understand the basic question which is there and that is what are binoculars?

What are binoculars or binos?

Binoculars in a very simple language are the two lenses or refracting telescopes which are in some way placed together as a unit. The way they are placed together is by using a nice plastic body or a metal body.Once you see an image through these telescopes they will appear bigger than the image is in reality.

Going by the principle of optics most of binoculars use the prism to bend the light before it enters the objective lens. That leads us to two things and those are what is an objective lens and secondly what kind of prisms are used?

What is a binocular objective lens?

The lens through which you view the object is the objective lens. The greater is the size of the objective lens the more light will enter the lens and it will be better viewing. This is definitely true but the disadvantage of this is that the lens size will become bigger which will mean that the size across the diameter (measured in millimeters) will be bigger. This will mean bigger and bulkier binoculars.

In the notation that you always keep hearing like 10×42 or 8×42, the second part which is the “42″ is the size of the objective lens and the first part of the specification that is “7″ or “10″ or “8″ is the magnification. This magnification means that the object will appear 7 times closer or 8 times closer or 10 times closer.

As far as binoculars magnification and the size is concerned there are various specification available in the binoculars manufactured by various brands.

However if you need to know the best one based on you need then there is this chart which I found out at http://www.just-binoculars.com/binocular_facts.htm

As far as magnification is concerned you would have heard about the zoom binoculars. The way zoom binoculars are called so is because in zoom binoculars you can adjust the zoom or the magnification within a given range. That is if the zoom binoculars specify 8- 22 then that means that you will be able to adjust the magnification of the binoculars starting from 8 times bigger object to 22 times bigger object viewing.

What is the best hunting binoculars specification?

The magnification range between 7x and 10x is the best when it comes to hunting. Of course, since it involves hunting then you should go for the rubber armored, waterproof and fogproof binos.

For birding enthusiasts the best binoculars are the 8×42. A lot of people use the 10×42 or the 12×50 specification binoculars also. The greater the objective lens diameter it is good for birding enthusiast as you can then have greater wide area viewing.

The thumb rule is – Go for the size of the objective lens which is greater than or equal to the magnification power. This is based on the eye relief which means the viewability of the eye. This will be explained in detail in my next post about eye relief.  More magnification means more blurred image as the light is spread then over a larger area . This in turn means that you will get a blurred image.

That is why the multiplication factor of 5 is best. The 5mm – 7mm is the best “exit pupil”. Exit Pupil is the amount of light that a human eye can accept.

Binoculars have many specifications and at times it becomes very difficult for a layman to understand what would be the best pair of binocular for him based upon his needs and specifications. One must keep in mind few of the salient features of an ideal binoculars at the time when you are buying.

Magnification power of Binoculars:

# Magnification power of any binoculars has a number ranging between 5 and 12, which means as to how many the oject or the target is magnified. Higer the magnification power of your binoculars, blurs the image. As such their is no such perfect magnification number, but number 8 is good for hunting, birding and navigation. If a person is looking for a high and powerful binoculars then that means you need  a tripod as well. Wheras the maximum magnification for night vision binoculars is usually 5.

Objective Diameter of Binoculars:

#   It is found that binoculars have two variables for instance 8×40 and 10×50. Here the first number menas the magnification and the other number signifies the objective diameter of the lens. Higher the objective diameter bighter is the image, which menas if you are looking at binoculars with 8 magnification then the best suited lens diameter would be 40.

Binoculars with specification of 10×50 would be better where the natural light is very low and you will need larger lens for viewing specially during fog and dawn time.

Lens coating of Binoculars:

# For a good picture quality coating of the lenses on your binoculars is very important. The coating of the lenses increases the clarity and brightness of the image and does not allow any reflection to enter which might effect the image. There are 4 ways the coating of the lenses is done:- coated, multi coated, fully coated, fullly multi coated. It is always advisable to buy fully coated or fully multi coated binoculars to have brighter, clear and sharper image. One should make sure at the time selection of binoculars to have waterproof or water resistant and should look for anti- fogging lenses.

In-built camera in Binoculars:

# Today most the binoculars have in-built camera, which helps to take picture it is beneficial for bird watchers and site seeing navigators. These binoculars with in-built camera are costlier than the reguls binoculars.

Always ensure what you are looking in a binocular and have a clear view about the purpose you might use  it, depending on your preference and needs this will make your expidition adventurous and exciting.

The hunting optics today are mafactured by good brands like Bushnell, Leupold, Zeiss, ATN, Swarovski and Nikon. Buying from these known brands is advisable as they provide top quality optics and the best information. It is always good to know the correct optics suitable for your rifle based on requirement.

Today market is flooded with numerous options. It all depends what kind of particular hunting optics you are looking for? Their are different optics available with the manufacturer which includes :- rifle scopes, night vision scope, spotting scopes, mount scopes, laser scopes, rangefinder, monoculars and binoculars. Monoculars is a single eyepiece contrary to a binocular which is dual eyepiece and can be used on a tripod. They are also available in high quality night vision monoculars.

In hunting optics rangefinder are the most popular. These optics work on high technology and with the in-built laser they can calculate the exact distance between the object and the shooter. The Bushnell Yardage Pro 450 is one of the most popular rated product available in market at a affordable price.

Brands like Nikon Buckmaster and Burris Landmark are the best suited binoculars for hunting. It is therefore very important to select the right optics depending upon your hunting needs. For example if you are out for hunting in closed area where the natural light is very low then you need a laser scope. And if you hunt long distance then high magnification rifle scope is right choice. Along with this you might also need lens diameter to view larger objects.

For a adventureous hunter it is always advisiable at the time of selection of binoculars to buy waterproof and fogproof hunting optics. A fixed magnification scope will be lighter as compared with a smaller lens size. A Good hunter will keep in mind the weight as the prime consideration at the time of purchasing the binoculars.

At the time of selecting the best hunting binoculars there are also other features to be considered which include magnification, eye relief, objective lens diameter, exit pupil and field of view. Based on your particular need and shooting style you will be able to select the best optics and will make your expedition adventureous.  

It is always recommended for any hunter to have a Bak-4 prism for a sharp, bright and a high quality image. For the purpose of protection and high image quality the hunting binocular optics should be fully multi-coated. It is always advisable while you are out for tracking to use Roof prism binoculars as they are more durable and sturdy.

While you are looking for outdoor optics, specially night vision hunting binoculars, compact binoculars or toughened waterproof binoculars are available in 8×42 and 10×42 magnification.  The 8×42 magnification is a good bet for hunting during night or early morning or any time during the day or evening when the natural light is dim. If you are out for hunting in a forest or in a bushy area then 8x magnification would be the best as your vision will be substancially be reduced. And on the contrary if you are in an open area where the natural light is better, then 10x magnification would be the best option, so that you can see quite far away.  

Few tips for choosing best hunting binoculars

• While making your choice for selecting the best hunting binoculars make sure that for what purpose your need them? Whether you are looking for hunting binoculars, tracking binoculars, marine binoculars or birding binoculars or compact or night vision binoculars or for fishing.
• At the time of choosing your binoculars, lenses are the most important component. Make sure that the lenses have been optically grounded and are well coated for protection. A multi-coated lens is highly superior in quality and more durable and sturdy. 
• Ensure that the binoculars are made of hard rubber shell good for rough and tough ususge. Make sure to buy binoculars of high quality and good make.
• Check for the perfect magnification you need based upon your requirement. If you are looking for hunting binoculars for viewing long distance then you should go for high powered binoculars and similarly if you are hunting in wooded area where the light vision is low and dim then  8x woud be the best mignification. Higher the magnification lower will be the image quality and lower the magnification higher wil be the image quality.
• Always ensure while making your selection for hunting binoculars that they are waterproof binoculars and their is anti fog coating on the lens. Make sure that the optics have a comfortable neck strap so that it is easy to carry. 
• The focal adjustment should be thoughly checked at the time of making your selection. Make sure it moves swiftly and smoothly for better results.

At the time of selectig the best hunting binoculars spend your precious time in researching and make sure that get exactly what you are looking for as that would make your hunting more enjoyable, exciting and adventures for the times to come.