Binoculars were created in 1608 and come in all shapes, sizes, qualities and powers. It was a Dutch optician named Hans Lipperhey who created the first devices for long distance viewing. Binoculars are ideal for your hikes and short excursions. For hunters and military, or simply to be able to follow and enjoy a nice play from your seat. You can use binoculars to enjoy your favorite activity. Binoculars are an ideal and faithful companion for the great naturist thanks to their incredible advantages. But they can also be very useful for classic activities such as theater, golf, etc.
How to choose the right pair of binoculars?
It is important to make the right choice when buying binoculars. It should be noted that each pair of binoculars has its own characteristics. Therefore, you should choose the one that best suits your activity and environment. From the strength of the mechanism and its specificity to its optical quality. All these criteria should be studied very carefully before buying.
First of all, when inspecting a pair of binoculars, you should recognize these two markings a x b. The "a" represents the magnification of the binoculars. The "b" expresses the diameter in millimeters. As an example, let's take the best-selling "8X32" model. Here the number 8 means that the object to be observed will be magnified 8 times more than in real vision. Then the number 32 shows the diameter of the object under study, the higher the number, the sharper the image.
A hiker or adventurer will need a more versatile and practical pair of binoculars, i.e. 8X32 or 10X42. Also, it needs to be smaller to be lighter. This means you can carry them around your neck or in a backpack. It is best to choose a waterproof binoculars in case of bad weather. You can also choose a rubber armor to avoid shocks. The most modern models will allow you to hunt without being seen at night.
If you are looking for a pair of binoculars to have a perfect field of view in the theater or during races, the compact 8X24 models are the ones you will find most suitable and convenient. You will be able to see everything with your theater binoculars hanging around your neck with a strap.
The taller model will be used to admire the stars and other comets, thus serving as a telescope. These observation devices guarantee a stereoscopic view thanks to their binocular characteristics and brightness. But for this use you will need a tripod to ensure the stability of the images.
Spectacle wearers can easily equip themselves without having to remove their frames. To do so, they should choose a model with easily retractable lenses. Some binoculars have modern adjustments to correct visual defects. However, with autofocus binoculars, you will have to wear your glasses. Therefore, you should make sure you have all the information you need before choosing a pair of binoculars.
How do binoculars work : focus/adjust ?
Once you have examined the equipment, you will need to know how to adjust it during use. If you don't, you may be tempted to leave it in a closet in your office. Or you can go back to the dealer for an explanation. We all know what the second solution leads to....
First, we'll start with adjusting the eyepieces. This is the easiest thing to do, but it should not be neglected. This adjustment will depend on whether or not the observer is wearing a scope. A pair of binoculares is usually equipped with eyepieces that you can easily take off or put on depending on your situation. These eyepieces are used to ensure the distance between your eyes and the binoculars to get a clear and complete image. Therefore, for those who wear glasses, the eyepieces should be retracted. For those who do not wear glasses, simply pull out the eyepieces.
Next, you must find the ideal width for your binoculars. This step is very important, as it will allow you to comfortably view your targets. What you need to do here is to make sure that the width of the eyepieces is at the same distance as your eyes. Then, you will only need to move the two sight tubes closer or farther apart to suit your eyes. You should make this adjustment while looking at an object that is quite far away. Make sure that everything you see with the left eye is the same as the right eye. That is, until you see only a circle in your field of view.
We will continue our adjustments by correcting the diopter. Diopter is the unit of convergence of lenses or other optical systems. It is essential to adjust it, as this will compensate for any differences between the eyes. The focusing wheel is usually located on the right eyepiece. But in some binoculars it may be behind the central focusing knob. So you should be careful, as the location will also depend on the brand of your camera. To begin with, you will first have to place an object in your viewfinder at a suitable distance, neither too far away nor too close. Now you'll set up your left eye by focusing with the center point. During the action, the other eye should be closed, to make it easier, you can place a hand on the right eye. Next, you will adjust the diopter of the right eye using the dioptric adjustment system. Don't forget that this time it is the left eye that you will have to close.
The last point will be the focusing of your binoculars. This is done in a very simple way, you just have to focus on the object you want to look at. This way, you will be able to see your target more clearly. But beware, if the above settings are not followed correctly, your eyes will try to counteract the lack of sharpness. This can damage your eyes or cause a severe headache. You can then make a note of the settings shown for your next observations.
A few more things to keep in mind when choosing the best binoculars
Adjusting the binoculars to obtain an optimal image is very important. To do this, even more detailed elements must be taken into account. These are eyepiece distance, diopter adjustment, visual focus and treatment of distorted binoculars.
- Eyepiece spacing
Eyepieces should be placed exactly in front of each eye. You should fold and unfold the binoculars in front of your eyes without fidgeting to achieve the ideal distance. This ideal distance is achieved when the image is clear and complete. If the distance is not perfect, the image will appear obscured or the images from the two eyepieces will overlap. This makes observation very uncomfortable. You should always make this simple adjustment whenever you loan your binoculars or fold them for storage.
- Diopter adjustment
The diopter adjustment allows you to adjust the vision for each eye. Sometimes vision can appear blurred on one side, making observation uncomfortable. Depending on the model, the diopter can be adjusted on one of the eyepieces or by means of the knobs near the focusing wheel.
To make this adjustment, simply aim at an object at a medium distance (about 10 meters) and focus approximately. Then turn the diopter adjustment wheel for each eye until you obtain exactly the same result for both eyes. Finally, refine the focus and correct the diopter adjustment again if necessary. One way to do this is to close one eye. Then, focus the other eye perfectly. Next, turn the diopter adjustment wheel until you have perfect focus in that eye. Perform the same diopter adjustment for the other eye.
To save time in diopter adjustments, you can memorize the position indicated by the mark on the dial. Note that some models have a diopter adjustment lock.
- Focusing your attention
As an observer, do not compensate your vision with eyestrain. Focus carefully with the center focus wheel. For long-term observation, always have perfect focus. This allows you to obtain clear, sharp images without straining your eyes.
- The position of the eyepieces
These viewing devices have eyecups on the eyepieces. They allow you to adjust the distance between the eye and the lens: eye relief. There are different systems for folding, pushing back or screwing. In general, with glasses, the eyepieces should be in the "up" position and without glasses, they should be in the "down" position. This avoids reducing the field of vision. On some models, you will have "notches" for intermediate adjustment.
- Fake binoculars
Your binoculars are distorted when you cannot see clearly or if you see two images that are slightly misaligned. This means that the prisms inside are no longer perfectly aligned. This can be caused by a fall, a bump or vibrations and shocks. In such a case, you should have them repaired by a specialist. Repeated use of distorted binoculars can cause eyestrain and headaches. In some cases, the problem is a malfunction of the diopter adjustment and can also be repaired.
How to measure distance with binoculars?
Calculating distance with binoculars is very simple, just follow these instructions. First, when looking through the binoculars, you will observe a distance scale in the center. This will define the distance of the objects you are observing.
Next, you will need to know the size of the object you are looking at. As an example, let's take an object 30 m high. Now we will count the number of lines this object occupies on the scale. Let's take 5 lines for the 30 m as an example. Then turn the scale ring to place the rangefinder on the "ANGLE" label. The arrow should point to 5.
Now we will focus our attention on the size of the object (30 m high) which will be on the center scale marked "OBJECT SIZE". Now move your gaze to the bottom of the scale and you will see the "distance" written on it. Right next to the inscription will be the actual distance of the object, e.g. 600 m away. This way, you can read how far the object is from your location. Now you know how to calculate the distance with a binocular.
More information on the operation of binoculars
We know that binoculars are binocular optical devices. They are a sophisticated magnifying device. They act as a kind of magnifying glass or zoom lens to observe objects at a long distance. For this purpose, they use curved glass lenses to magnify the images. To maintain brightness, a prism is used to bend and reflect the light entering the lenses. There are BK-7 prisms that are of lower quality than Bak4 prisms. You can also find binoculars with higher quality prisms than the latter.
Each binocular has its own capability and it is up to you to choose the one that suits you best. There are two numbers on the binoculars to help you. One number indicates the magnification power and the other the objective lens diameter. Some types of binoculars guarantee you night vision. For this purpose, light amplification or infrared-to-visible light conversion devices have been incorporated into the equipment.
Binoculars, or spotting scopes, are optical systems with several lenses at the end of each tube. Ambient light enters through the lenses and the mixture allows close-up images to be obtained. In the case of night vision binoculars, also known as night vision binoculars or night vision goggles, they are equipped with a brightness amplification system. Thanks to this process, night vision is possible and can be seen in total darkness or in a low-light area.
As the lenses are convergent systems, the images are rotated (up/down, left/right) like a telescope. To observe the rectified images, an optical vehicle with a prism system is interposed in the light path. This makes it possible to double the light beam and reduce the overall size of the instrument and the residual light. Another advantage of this optical vehicle is that the folded optical beams remain parallel. This makes it possible to increase the distance between the optical axes and the objectives, while maintaining a distance between the output axes equal to that of the observer's eyes. Thanks to this device, a child or an adult with different distance between the eyes can use the same binocular. They will have a greater sense of relief, and a magnification by the device greater than one.
Images are magnified by the eyepieces, which act like magnifying glasses and consist of several lenses in two tubes. The tubes are designed in such a way that a central mechanical axis can help adjust the interpupillary distance. This makes the binoculars adjustable from person to person. In addition, one of the eyepieces is adjustable to correct for differences in visual quality. This is the diopter correction of the observer's two eyes.