Before you get into binocular comparisons you should at least know what the terms used to determine the quality of a pair of binoculars means. Once you understand what some of the technical jargon means you will have better understanding of the best way to use your binoculars too.
We are going to assume that you are looking for the reviews in order to determine “What is the binoculars?. Or another way to look at the question is to ask “Who makes the best binoculars?”.
Before you launch into your binocular review comparison you should learn what terms like “coated” and “multi-coated” mean. You should learn what types of prisms work best and why a 10×50 binocular is probably not the best for a hunter.
The best hunting binocular reviews will not be the same as the best astronomy binoculars or the best astronomy binoculars. Some of the basic considerations when looking to purchase a binocular are the same considerations you should consider when buying the best ar 15 scope.
They both use optics to make what you are looking at appear closer.
There are two main considerations when looking for quality; mechanical and optical quality. The price of a binocular is primarily affected by the quality of its components. Optical quality includes things like the type of glass selected for the lenses and prisms. Also, the eyepiece design and the amount of care taken in the grinding and polishing of the glass elements. Finally what is the quality of the anti-reflection coatings on the glass elements.
Mechanical quality items include things like the lens barrel material (metal or plastic). Are the binocular barrels made of one piece or two piece construction? How are the glass elements mounted and secured in place?
Anti-reflection coatings are used by nearly all manufacturers today. These coatings are used to facilitate light transmission. When looking to purchase binoculars be sure to look at how the manufacturer describes the anti-reflection coatings: If they say “Coated”, that means they have used a single layer antireflection coating on some lens elements.
The term “Coated’ does not mean that all glass elements are coated. Most commonly, they only coat the first and last elements (the ones you can see).
A step up on binocular quality from “Coated” is the term “Fully Coated”. This means that ALL air to glass surfaces are coated. And remember that “Fully Coated” is much better than “Coated”.
Next step up in the quality is “Multi-Coated”. This is a somewhat confusing term and it means some glass surfaces have multiple layers of anti-reflection coatings on them (again, usually the first and the last) and the other glass surfaces have a single layer of anti-reflection coating on them).
Top of the line is “Fully Multi-Coated” and that is what you should be looking for. This means that all air to glass surfaces have been coated with multiple layers of antireflection coatings. Top of the line and without a doubt, the best way to go.
As an addition, technological advancements are now allowing ‘ruby’ or red multi-coatings too. These coatings are designed and applied in order to further reduce glare when using the binoculars in very bright light.
When you see a description of a binocular, you will see two sets of numbers, like 7×50. The first number is the ‘magnification’ number and determines how close the object will appear.
For example, 7×50 means the objects will appear 7 times closer than when viewed with the unaided eye.
The most common binocular magnification factors are: 6x, 7x, 8x, 9x and 10x.
If you happen to be looking at variable zoom binoculars, then you may see something like 5-20×50. This means that the magnification can be varied from 5 times to 20 times what would be seen by the unaided eye. For variable zoom binoculars, almost without exception, the performance at the lowest magnification setting is better than that of the higher magnification settings. Technically, the reason for this is that in order for the performance to be the same at the higher magnification setting, the amount of light must be increased by the same magnitude. Images will be dimmer as the magnification increases.
Objective lens (diameter) The second number in our example above, 7×50 represents the diameter (in millimeters) of the objective lens. So 7×50 binocular means that the front lens is 50mm in diameter. The importance of this number is that the larger the front lens, the more light entering the binoculars (and thus the more light that can get to your eyes). So, a set of 7×50 will see much better in dim light than a pair of 7×25.
Arming yourself with a little knowledge will help you in deciphering what binocular reviews are talking about. Just keep in mind that with more magnification and larger objective lens size means the weight and bulk really goes up too.
Plus the higher the magnification, the ‘shakier’ the image will be when looking through the binoculars.