Do you need a pair of binoculars for hiking or for some more professional activity like hunting? Well, the market is huge, and it can be difficult to choose from hundreds of binocular models. This article is intended to help you select the model that best fits your needs the best if you follow our guide.
KNOW THE TECHNICAL TERMS
Magnification and lens diameter
If you have done some research on binoculars, you may have noticed that when you talk about optics, numbers like 9×63, 7×50 and others like that are specified for each model. These numbers make it possible to inform you about two main characteristics of the binoculars in question. The first number indicates the magnification while the second one informs you of the objective lens diameter. Thus, for 9×63 binoculars, the magnification factor is 9x and the outer diameter of the objective lenses is 63mm.
Another characteristic common to all pairs of binoculars is their mode of manufacture. You may also have noticed names like Porro prism or roof prism. These are the technical terms that tell the format (type) of binoculars. Optics with Porro prisms are the most popular on the market, because it is the oldest technology but also the most economical.
They are easily recognizable by their two widely separated objectives. The roof prism is a much more recent technology and has been reserved for “high-end” optics – although it seems that in recent times, manufacturers are increasingly opting for this format. These two manufacturing methods affect the size of the binoculars,
The magnification, the diameter of the lenses and the type of manufacture of the binoculars are not the only characteristics to consider when you want to acquire a new pair of hunting binoculars, other important factors are also to be taken into account. Definition of some more technical terms would follow shortly, these are meant to guide you to a binocular that would perfectly suit your needs.
The exit pupil
The exit pupil corresponds to the crossing of the light beams at the exit of the binoculars. Also referred to as the eye circle, it is more concretely the black circle you observe when you move the binoculars about 30m away from your eyes.
The ideal situation is that this exit pupil, obtained by dividing the diameter of the objectives by the magnification (for binoculars 7 × 50: 50/7 = 7.1 – the exit pupil is of 7.1mm), is greater than the diameter of your eye pupil.
Our pupil dilates under low light conditions and can get to a diameter of up to about 7mm for an adult. Thus, for optimal viewing conditions, opt for a pair of binoculars whose ocular circle is greater than the diameter of your pupils.
The twilight index
This index, purely mathematical result, is often questioned by some manufacturers who consider it not revealing the actual performance of a binocular’s optics. The twilight index of a pair of binoculars is the result of the following mathematical calculation: √ (Magnification x Diameter of objectives) – √ being the symbol for “square root”. Take for example a 7×50 binocular. The twilight index is given by: √ (7 × 50) = 18.7 – the twilight index of a pair of binoculars 7 × 50 is therefore 18.7.
The field of view
This is the expression, in meters, of the portion of a landscape or object observed at a distance of 1000 meters. The larger the field of view, the easier it will be to locate and track an object like a bird. Conversely, the higher the magnification of a pair of binoculars, the lesser the value of the field of view.
So what if you wear glasses?
Some binoculars have retractable eyecups. These are essential for glasses wearers. It will allow you to adapt the exit pupil to your view. To check the presence of retractable windscreens, simply unscrew the eyepieces from the binoculars. Note that all the points discussed above are also to be considered in the choice of your future optics.
It is not a must to purchase a high-end model to own a pair of binoculars that suits you fully, some entry / mid-range items will have the right combination of features to competently meet your expectations.
Binoculars adapted to your needs
Beyond these technical points that are certainly important, you must also consider how you intend to use your binoculars. If you hunt on a small pond in the middle of the plain, without shades, or if you hunt on a lake of several tens of hectares, then your needs are not the same and the choice of binocular you make for both purposes should be different. Here are the factors you need to consider in order to find the pair of binoculars that will completely satisfy you.
Your hunting/observation area
This point will allow you to define the magnification that will best meet your needs. If you hunt on a large body of water like the sea for example, you need a pair of binoculars that will allow you to observe but also to identify birds at great distances. In this case, choose a pair of binoculars with high magnification say 9x or 10x.
On the other hand, if you are hunting in a more confined puddle, you prefer a wide field of vision which will enable you to observe all your targets quickly, binoculars with magnification of 7x or 8x seem more adapted for this purpose.
The needs in brightness
If you want to be able to clearly identify your targets, you must pay close attention to this point. You will need to determine the brightness requirements of your future pair of binoculars. Generally, the more the brightness and better your observations, and in some cases, the brightness must take precedence over all other features.
Take for example a pond tucked into a valley, or surrounded by trees, the shadows cover most of the puddle. What good is having binoculars at 10x magnification if you cannot see at 10 meters? Choose binoculars with large lenses and a high twilight index.
Do not forget also to consider for areas like this, the diameter of your pupil under these conditions since they will significantly dilate, you would need a device with a large exit pupil.
Your budget might be tight and not sufficient to purchase a pair of binoculars costing several thousands of dollars. However, be rest assured that a pair of binoculars chosen carefully, taking all the points above into consideration will surely offer you great observation quality.
It is always better by far to own an entry-level or a midrange pair of binoculars that fits your needs perfectly rather than buying just any optical device under the pretext that it is categorized in the high-end category.