Reasons to own a pair of binoculars
If you are in a dilemma whether to buy a telescope or binoculars, don’t hesitate and buy a telescope. However, since you are not in such a dilemma, we will tell you that binoculars also have some advantages.
Basically, binoculars consist of two terrestrial telescopes. This “terrestrial” (lat. terrestris – earthly, terrestrial) means that there is a prism in the instrument that corrects the image of the observed object.
Namely, the lens twists the image and what is above we see below. This does not bother astronomers because there is no up and down in space anyway, but it would be quite impractical to look at upside down objects on earth through the instrument. That is why this correction is made.
So, the lens in the binoculars creates a reduced, real and inverted image, which is corrected using prisms and thus sent to the eyepiece.
Binoculars are usually engraved with two numbers that describe their main features. Let’s say it says 7×50. The first number (7x) is the magnification information. In practice, this means that an object 700 meters (kilometers, etc.) away seen through binoculars is seen as if it were 100 meters (km, etc.) away from you.
The second number is the diameter of the objective and it tells us about the light intensity of the binoculars. The larger the diameter, the greater the amount of light entering the lens and the objects you observe are brighter and clearer.
This, of course, is of particular importance for astronomical observations, because these observations are reduced mainly to the observation of low-luminosity objects (stars, nebulae, etc.). For night observations, you should therefore have a lens with as large a diameter as possible. It’s the light output that matters, not the magnification. After all, with a binocular that magnifies over ten times, you can’t see anything special if you don’t have a stand for it because you need to keep it still.
If you have binoculars – great! It’s a great device, sometimes more useful than a telescope. Here’s why.
- First of all, binoculars are a mobile thing, they are small and easy to carry.
- The light beam in it passes the same length of path as in the telescope, but due to refraction in the prisms, the entire path is placed in a smaller tube.
- Then the prisms make the distance between the two lenses larger than the pupils, which leads to a good stereoscopic effect.
- Objects viewed through binoculars are more plastic than viewed through a telescope.
- Binoculars have a larger field of view than telescopes (because their magnifications are smaller), and this gives them an advantage in some observations. For example, when observing variable stars, this is very useful because the width of the field of view depends on whether you will be able to see the variable at the same time as the corresponding comparison star.
- Due to the wide field of view, comet hunters also use binoculars. Not to mention the price.