How to choose a telescope ?
Today Astronomy is a passion that brings together more and more people. This requires some knowledge. Observation can be done primarily with the naked eye, but the more knowledge you have, the more you will want to push the observations. That is why choosing the right instruments to observe the sky is essential.
The instruments of observation of the sky have been perfected for a few decades. Many changes have been made to better meet the expectations of users who are increasingly numerous and becoming more and more demanding.
What criteria ?
The choice of a telescope will be based on several criteria.
While there are many elements that can be taken into account, there are essentially three functions to remember when choosing a telescope, namely:
- Enlarge the object you want to observe
- Bringing brightness
- Get an excellent resolution
The diameter is the criterion at the top of the list in the choice of your device. It is usually expressed in millimeters, it is important at two levels: the brightness and the resolution of the object to be observed. The principle is the following, the larger the diameter, the more the object under observation will be clear and bright.
The second characteristic is the focal length. This is the distance the light travels through the telescope tube. The focal length is expressed in mm, the length of the focal length gives you an idea of its magnification power. In principle, the higher the focal length, the more the device can magnify the observed object.
And finally, the third characteristic to see is the opening. This is the ratio of the focal length to the diameter of the instrument. In other words, it defines the optical performance of the tube.
With a focal length and a large diameter, the camera will offer a better resolution. While if the focal length and diameter are small, the instrument will bring a little more brightness.
Choose the right telescope for you
If you want to know more about which telescope you should choose for your observations, visit the page here : Choisir un telescope
Before buying a telescope, you must already understand how you can use it. You have to ask yourself a few questions, especially those related to the use you plan to make.
In fact, you will not be able to use the same telescope if you just want to see the starry sky and want to see objects in the solar system much more accurately. When choosing your telescope, you will need to define what you want to observe in order to find the instrument that best suits your needs.
Observe the Moon
As we mentioned earlier, you will have to look a little bit at the diameter of the device, which will also be called “opening”. Most of the time, the first thing people want to see when they have a telescope in their hands is the moon. It is considered that, for the simple observation of the moon, it is enough to opt for a telescope of 60 to 70 mm of opening. The more details you want to observe, the more you will have to lean towards an accessory with a larger opening. For example, to admire every detail of the moon, it will be advisable to turn to a 100 mm aperture. For further observations, you can turn to a much more powerful telescope.
There are several types of telescopes. Versatile telescopes are the classic models. They allow to observe the different objects of the sky. But it remains advisable to choose a telescope that is specifically intended for the field of observation on which you work.
Note that astronomical binoculars can also be the ideal solution for observing the moon and some planets for a small budget. It also allows you to become familiar with Astronomy smoothly and this accessory will be less bulky than a telescope.
Observe the planets
For the observation of the planets, it is necessary to know that in principle, a planet, being close to the sun, is already luminous by nature. In this case, the telescope will only be used to magnify the image, so that all the details are clearly visible.
Keep in mind that some planets are invisible through a telescope, especially if they are too close or too close to the sun. For example, some telescopes can enter Mercury, but it’s still very difficult.
Uranus and Neptune is not just the little points in your starry sky. The observers of the planet are mainly Mars, Venus, Jupiter and finally Saturn.
It is advisable to take a telescope with an azimuth mount, which allows you to follow the movements of the stars more easily and comfortably. If you take a go-To version, it’s even better. It is a system that can turn the telescope into a robot, just indicate the star to be observed and the telescope will do the research for you.
Observe the deep sky
On the other hand, to observe the deep sky, it will be necessary to foresee light. Compared to the planets, the deep sky remains faint. In this case, we avoid enlarging the image so as not to lose brightness. It is then advisable to take a telescope that highlights the diameter, but there is no need for a large focal length. The goal is to widen the vision through a tube that is in principle open.
In case you want to observe the galaxies and nebulae present in the sky, it will turn to the side of a high performance material with, at least, 250 mm in diameter.
An equatorial mount is also a very practical solution. This type of frame allows you to follow the movement of stars that revolve around the polar axis. Some models may have small engines, others not.
To keep in mind
You must keep in mind that this type of purchase represents a significant amount. The more efficient and precise your telescope is, the more expensive it will be. When buying a telescope, it is also important not to be too demanding. For example, you will not be able to observe every detail of the planet Saturn with a telescope with a 70mm aperture, but some are good enough to let you see its beautiful rings. It all depends on the budget you are going to invest.
You should also keep in mind that the quality of your observations will depend on where you are. Indeed, you must make sure to have as little light pollution as possible. This means that the less illuminated the place you are, the more likely you are to distinguish the elements from the sky in a clear and precise way. In general, it is inadvisable to try to observe the sky when one is in the middle of a city center. Places such as the countryside or the edge of the ocean will be favored because there is no artificial light during the night.