TelescopeReview

There are three basic types of telescopes refractors, reflectors, and catadioptrics. All three designs have the same purpose, to collect light and bring it to a point of focus so it can be magnified with an eyepiece for examination by the eye. Each does this work differently, though. And each has advantages, as well as disadvantages.

Overview of the Basic Types of Telescopes

Reflecting Telescopes

Pros:

Ideal for moon, planets, and stars

Good for distant terrestrial viewing

Require little or no maintenance

Classic telescope design

Cons:

Most expensive per inch of aperture

Cost/bulk factors limit maximum size

Less suited for faint, deep-sky objects

Refracting Telescopes

Pros:

Least expensive per inch of aperture

Large apertures for deep-sky viewing

Reasonably compact and portable

Delivers very bright images

Cons:

Not well suited for terrestrial viewing

Slight light loss due to mirror system

May need simple mirror alignment

Catadioptric Telescopes

Pros:

Easy to use, compact and portable

Excellent optics provide sharp images

Great for astrophotography

Best all-purpose telescope design

Cons:

Most expensive telescope type

Slight light loss due to mirror system

Somewhat unusual appearance

Refracting Telescopes

Refracting telescopes employ two lenses to collect, focus and magnify more light than is otherwise possible with just the naked eye. This is the alternative to the reflecting telescope, which uses a system of mirrors to do the same. Refracting telescopes are widely considered to be sturdier and require less maintenance than their mirrored counterparts.

A chief reason that refracting telescopes require such little upkeep is that the lenses are fixed in place more firmly, meaning there will be no minor adjustments to be made on a regular basis. Also, although the technology of refracting telescopes is much older, the process is much more refined and therefore more reliable.

While you will enjoy the benefits of reliability and low maintenance, the initial cost of refracting telescopes is usually higher. This is because they must be ground and positioned to very precise specifications.

Just about every company in optics makes a refracting telescope, but you should especially check out those produced by Celestron, Meade, Zhumell, Orion, and Bushnell. These are excellent consumer brands geared toward the mass market, but many of them also produce institutional quality telescopes for use in observatories.

If you’re just getting started out in astronomy, the refracting telescope is recommended for the reasons mentioned above. Even after you’re sure you want to invest more money in your new hobby, you can buy plenty of accessories such as photography equipment and tripods before you need to upgrade.

Examples

Omni XLT 150 R

Ambassador 80 AZ

NexStar 102 SLT

80 LCM

Reflecting Telescopes

The mirrors and other components in reflecting telescopes are considerably less expensive. Mirrors can be fine tuned for optics much more easily than lenses can be ground, resulting in less expensive telescopes. If cost is your primary concern, you’ll probably want to get a reflecting model.

However, they aren’t always the best for beginners, as reflecting telescopes will require a little more maintenance as compared to refracting telescopes. Mirrors require regular recoating, as often as once every few years. They also must be handled very carefully as compared to refracting telescopes. Finally, a reflecting telescope requires more collimation, or adjusting, of the optical components.

Reflecting telescopes do usually create a more faithful reproduction of the sky than refracting telescopes. Generally you won’t have as many problems with “aberration,” or the faint colours that surround some celestial bodies like Jupiter and the moon.

For anyone brand new to the practice of astronomy, convention says that the refractor is more practical choice. If you know for certain that you’ll be using your telescope and regularly practicing astronomy, though, you’ll probably want to get a reflecting telescope right off the bat. Reflecting telescopes are better for viewing very faint objects in deep space and are considered preferable for astrophotography.

You’ll find great selections of reflecting telescopes and all relevant variations of them from brands such as Celestron, Meade, Zhumell, and Bushnell. These brands are considered to be the best in consumer optical products ranging from binoculars to telescopes.

Examples

PowerSeeker 127 EQ

AstroMaster 114 EQ

AstroMaster 130 EQ

Sky Prodigy 130

NexStar 130 SLT

Catadioptric Telescopes

A catadioptric telescope is a hybrid of both reflector and refractor telescopes. The name is derived from its components; lenses on refractor telescopes are diotropics, curved mirrors are known as catoptrics.

The catadioptric design is advantageous because it offers greater error correction and a wider field of view. Because both lenses and mirrors are employed, the high manufacturing costs of grinding lenses can be mitigated.

Just like in reflecting telescopes, mirrors in catadioptric designs can correct spherical and chromatic aberrations created by lenses. Coma, another aberration that is typically a problem with reflecting telescopes, can be corrected with a good catadioptric design.

Of all the designs of catadioptric telescopes, the most popular are the Schmidt-Cassegrain and Maksutov-Cassegrain models. Each of these are popular for their comparative ease of use and mobility. Catadioptric telescopes allow all their optical components to be present in a single tube, creating a much more compact and portable telescope.

As mentioned, most catadioptric telescopes are of the Schmidt-Cassegrain or Maksutov-Cassegrain variety. Other variations include the Maksutov-Newtonian and Schmidt-Newtonian. The variations all have to do with the thickness of the corrector plate and the angle of reflection.

Because they are so popular with amateur astronomers and newcomers, all major optics firms produce a good selection of catadioptric telescopes. You’ll find great offerings from Celestron, Bushnell, Galileo, Zhumell, and Meade, among others.

Examples

NexStar 4 SE

NexStar 6 SE

NexStar 8SE

NexStar 127 SLT

CGE Pro 1400 SC

CGE Pro 1400 HD

CGEM 925 HD

The telescope of our time – what is it? This is not just a spyglass that consists of the most basic functions as it once was. A modern telescope can be called a “computer” telescope because it consists entirely of all necessary programs. Gradually, it turns from an ordinary astronomical device into a device capable of teaching astronomy. This improved model has a vast range of primary and additional functions that make life easier and better for both astronauts and an amateur of astronomy as a science.

First, you need to figure out what a telescope is in the modern sense. A telescope is an astronomical optical instrument to observe celestial bodies and obtain a magnified image of distant objects. The telescope performs all these functions by collecting electromagnetic radiation, which, as we know, can also be different. According to this principle, telescopes are divided into optical, radio, X-ray, and gamma.

Telescopes of the 21st century have gone through many years and centuries of refinement to get the look and functions they have today. The Dutch master Hans Lippersgei from Middelburg is considered the inventor of the first optical telescope. Still, the official date of appearance is 1609, together with Galileo Galilei as an inventor, when he assembled a three-fold spyglass from lenses and began to study the sky.

Each type of telescope is worthy of attention, so let’s take a look at each of them.

1.       Optical telescope – a tube established on a mount equipped with axes to aim at the object. The visual part of the telescope has a lens and an eyepiece. Instead of an eyepiece, a camera roll or a matrix radiation detector can be placed in the focal plane of the objective. According to their optical design, most telescopes are divided into:

•         Lens (refractors or diopters) – uses a lens or lens system as the objective.

•         Mirror (reflectors or catoptric) – a concave mirror is used as a lens.

Optical systems of mirror telescopes usually consist of two mirrors: the main one and the auxiliary one. The primary mirror reflects all the collected light onto a small extra mirror, which directs it to the observer or the photodetector and builds an image of the observed object. Why is the primary mirror made up of a plurality of individual mirrors? The fact is that unique small mirrors are made controllable, thereby realizing the principle of adaptive optics, which is designed to compensate for deviations and restore the origin (flat) shape of the wavefront, which is distorted in the process of entering the telescope.

•         Mirror-lens telescopes (catadioptric) – a spherical primary mirror is usually used as a lens, and lenses are used to compensate for its aberrations.

2.       Radio telescopes – they are used to study space objects. The main elements of these devices are the receiving antenna and the radiometer. The radio range is much more comprehensive than the optical one; therefore, different designs of such telescopes are used, depending on this range. For instance, for the long-wave region, telescopes with many receivers are used, and semi- or full-swing parabolic antennas are used for more short waves.

3.       Space telescopes – they work outside the Earth’s atmosphere. The most famous today is the Hubble Space Telescope, which has discovered many exoplanets and space events; it was launched in 1990. It was replaced in 2018 by the James Webb Telescope.

4.       X-ray telescope – designed to observe distant objects in the X-ray spectrum. They usually need to be raised above the Earth’s atmosphere, which is opaque to X-rays to operate. Therefore, telescopes are placed on high-altitude rockets or artificial earth satellites.

5.       Gamma telescope – designed to observe distant objects in gamma radiation spectrum. They are used to study gamma-ray bursts and the nature of dark matter. A distinction is made between space gamma-ray telescopes, which detect gamma quanta directly, and ground-based Cherenkov telescopes, which set the disturbances caused by gamma quanta in the atmosphere.

At present, the efficiency of receivers in the optical range, which is understood as the function of detected quanta from the total number arriving at the sensitive surface, is approaching the theoretical limit (100%), and other improvement paths are associated with an increase in the receiver format, acceleration of signal processing, etc.

Why do we need such improved telescopes compared to their ancestors, which underwent so many years and centuries of evolution? They bring us closer to solving the problems posed during the existence of life on the planet. The tasks of modern astronomy include:

•         The origin of the Universe;

•         Mechanisms of formation and evolution of stars, galaxies, and planetary systems;

•         Physical properties of matter in extreme astrophysical conditions;

•         Astrophysical aspects of the origin and existence of life in the Universe.

With the improvement of instruments, these tasks have become a little closer, but these tasks remain very difficult and require a lot of time to solve.

To obtain the maximum information about astronomical objects, a modern telescope must have a large surface of collecting optics and high efficiency of radiation detectors. In addition, observational interference should be kept to a minimum. Furthermore, to natural interference (for instance, cloudiness, dust formations in the atmosphere), the threat to the existence of optical astronomy is posed by the growing illumination from settlements, industrial centers, communications, and the technogenic pollution of the atmosphere. Modern observatories are built in places with a favorable astroclimate, which there are very few on the planet.

What conclusion can we draw? Telescopes today have undergone significant evolution and have become absolute lifesavers for astronauts and even astronomy amateurs who want to learn more profound about the depth of space. Are telescopes ideal today? No, but they are as close to the ideal as possible and continue to improve today.

Since childhood, the theme of space has been alluring and mysterious for each of us. Many of us dreamed of becoming astronauts or spacemen to immerse ourselves into the world of the beauty of stars and planets and study them better. It doesn’t matter if you are a child or an adult- the mysteriousness of the space attracts you. Being directly in such an area and becoming a spaceman is a challenging task, but another way to get closer to this topic is to purchase a telescope. There is a wide variety of them; you only have to choose which one is right for you. There are both ordinary telescopes for adults and the younger generation – children. They differ from each other slightly by parameters and design, so this topic is worth your attention.

What is a telescope? A telescope is a device that collects electromagnetic radiation and projects the resulting image onto a lens. So, what are the main types of them that adults could acquire?

The second name of these telescopes is refractory ones.

• Lens – they are made based on biconvex lenses that collect light from objects in a specific focus. They have a reliable design, sealed tubes, little influence of temperature and humidity on them, and can be used even for terrestrial viewing.

• Specular (reflex) – for them, convex mirrors are applied, which allows a lens eyepiece at the focal point to see an image that is clear of chromatic and spherical aberrations. They have small dimensions, no chromatic distortion, they are convenient for photographing astronomical objects, and these devices are adapted for observing faint objects in deep space.

• Catadioptric – using both lenses and mirrors results in excellent high-resolution images. They have a wide field of view, they are compact and portable, and devices of this type have minimized the impact of durable air on picture quality.

It is necessary to remember one crucial detail- the larger the aperture diameter is, the more you can see. When choosing a telescope, you don’t need to rely on magnification – you can change it by applying a different eyepiece.

It is also necessary to consider the focal length and mount. It can be azimuthal, equatorial, Dobson mount, and automated. An adult can use any of them, but the azimuth is the easiest one to use.

What can be said about kids? If children begin to be interested in astronomy from an early age, then a difficult question arises for parents: how to choose a telescope for a kid? It is necessary to consider many factors in the process of buying such a device, ranging from the availability in understanding during use for a child and ending with the appearance and dimensions. The optimal age for starting observations is 8-10 years; at this age, they can master a small and not too complicated telescope, examining celestial objects on a balcony or in a courtyard.

The attention of astronomy beginners, including children, will primarily be attached to close and bright objects. They include the Moon, planets, various stars. It is unnecessary to have a very expensive and powerful telescope to view such things. A small, simple telescope will be entirely enough. Even it can delight a child, who can see craters on the Moon, Jupiter’s companions, and other beautiful things.

Like telescopes for adults, telescopes for kids are divided into refractors and reflectors. The primary reflector objective lens is the leading and auxiliary mirrors, which makes the design more complicated, and it will be necessary to adjust the device regularly. If a child is interested in galaxies far from our solar system, then it will be essential to buy a reflector telescope and gradually teach kids to tune it. Refractors benefit because of easiness in use because the lens system is more straightforward and more resistant to external factors. Refractors can also be applied for ground-based observations. They provide an inverted mirror image, and in addition, these telescopes include a reversible eyepiece or diagonal prism for direct imaging, which will be helpful for terrestrial observation. A device with a lens diameter of 40 to 90mm is perfect for kids.

What about the mount? For children, the azimuth mount is the best suited since it is easy to use, and the child can quickly learn how to move the telescope horizontally and vertically and adjust the height of the tube.

It would be wonderful if the telescope had some atlases and teaching aids and several eyepieces in the kit.

So, we can conclude that telescopes now have a wide range of diversity, which provides an excellent choice for big and small observers of the starry sky. For both cases, it is necessary to consider some parameters and characteristics of the telescope; it is easier for adults to understand the functionality and design of the device, while the kid will need your help in crucial moments of the device’s operations. In any case, the telescope is a suitable device for all people, regardless of age!

Each of us, at least once in our life, was visited by the thought, “I wish I could look at these stars through a telescope!” For a long time, people had a dream of being at least a little closer to the sky, understanding its essence, seeing it closer, and getting to know it. Previously it was not possible until Galileo Galilei in 1609 created the progenitor of the modern telescope – he improved the telescope by making it with a threefold magnification. Centuries passed before telescopes reached the level we have now. But how to choose among such a wide variety exactly that telescope ideal for a particular person?

First of all, you need to answer some questions: who will observe through this telescope- a child or an adult, and whether you will have enough time to study astronomy – in other words, will you be an amateur, occasionally looking into the lens, or you will become a more professional observer. The parameters for choosing a telescope depend on these questions.

What do you need to look for in a telescope? If a telescope is required mainly to observe the starry sky, then it is unnecessary to give a direct image of objects and focus on close ground objects. It allows you to see even fainter objects. Over time, if you seriously engage in this science, you will desire to study various specific things in space, such as distant galaxies, which will lead to the need to purchase a telescope with a large lens diameter. Some parameters need to be considered while choosing a telescope:

• Optical design is the basis of the telescope; they are mirror (reflex), lens (refractory), a mirror-lens.

• Objective diameter – the larger the objective diameter, the greater the telescope’s aperture and resolution. So it becomes possible to see dimmer objects. This parameter dramatically affects the dimensions of the device and its weight.

According to this parameter, telescopes are divided into long-focus and short-focus. •        Focal length is a particular distance at which this telescope can focus. A long focal length means a larger magnification but a smaller field of view and aperture ratio. Small focal length – on the contrary – means slight exaggeration with a large area of view.

• A pry bar – a method of attaching a telescope to a tripod.

o Azimuthal – which freely rotates in two planes

o Equatorial – tunes to the pole of the world and allows you to see celestial objects, knowing their hour angle

o Dobson mount – a type of azimuth mount that will enable you to establish larger telescopes.

o Automated – with GPS, it is applied for automatic guidance to celestial objects.

The optical component is one of the most important in choosing a telescope. That is why it is necessary to take into account some of the features of each type of optics:

• Refractor – its objective lens is a lens system that collects and concentrates light. They have a reliable design, sealed tubes, little influence of temperature and humidity on them, and can be applied even for terrestrial viewing. The disadvantages include the fact that they have a large mass compared to reflectors and combined telescopes and the fact that they are not suitable for viewing dim galaxies and nebulas.

• Reflector – the lens of the device consists of the primary and secondary mirrors, the main one – collects light and directs it to the secondary, and then it reflects the rays towards the eyepiece. They have small dimensions, no chromatic distortion, are convenient for photographing astronomical objects, and are adapted for observing faint objects in deep space. The disadvantages include a long time of thermal stabilization, inapplicability for ground-based observations, and the fact that a coma is noticeable at the edges of the field.

• Combined – mirror-lens optical system. They have a wide field of view; they are compact and portable and have minimal impact on picture quality from durable air. Between disadvantages are long focal length, long thermal stabilization time, and problematic obtaining of a large–aperture device.

So you will ask: how to choose the best telescope? We already know the parameters for selecting telescopes, their basic – optical system, and what they are. The main rule when choosing this device is an important fact – the larger the tube diameter is, the more you can see. Magnification is not the main factor because it can be changed with the additional eyepiece. Therefore, the diameter of the aperture is a parameter that you need to rely on. It is always indicated in the name: for instance, Sky-Watcher BK 1149EQ2 has an aperture of 114mm. The pry bar is an equally important part. The more powerful it is, the more stable the telescope is, and the more stable the picture is. Do not forget that almost any telescope can be improved.

Choosing a telescope is a responsible and challenging process. Many factors need to be considered when selecting a device – mount, aperture, focal length, and optical design. But knowing the features of each of the parameters, you can make the right choice!

 Still, one rule must be noticed – do not buy a telescope with the expectation of a lifetime because this device is relatively highly specialized and requires handling skills that a beginner may not possess.

A modern observer of the starry sky cannot do without one instrument – a telescope. If you decide to buy a telescope, you need to know the basic facts about it, what it is, which types it has, how it differs from other optics, and what usage it can have. Whether you are a professional or a beginner learner of astronomy – regardless of this fact, this device will be a necessary attribute in your luggage.

What is a telescope? A telescope is a device that helps us to observe distant objects by collecting electromagnetic radiation. It is used in astronomy to study the night sky and photograph space things. Galileo Galilei made the first such device in 1609, and it looked like a spyglass in appearance. It is also necessary to understand how such a device works. In its classical form, this is a tube established on a mount – a rotary support device that sets precise guidance to objects of interest. The optical part of the device includes an eyepiece and a lens. These components provide an increase of distant objects, and the degree of magnification depends on the focal length between these two components on the lenses installed there. The most famous telescopes are diopter, catoptric, combined, radio telescopes, and infrared.

• Dioptric – a classic device with lenses, their principle of operation consists of the light collected by the lens from the bodies on the objective lens; the primary condition of work is the coincidence between the focus of the objective the eyepiece.

• Catoptric – the central part is a concave mirror, on which light is collected and reflected on the eyepiece. Such devices have a complete transmission of the light spectrum, and they show all the details of the object under study- color, brightness, depth, etc., but have a limited view.

• Combined devices – combines a lens and a concave mirror. They have a high-quality image and a wider viewing angle than specular telescopes. They also have two subspecies – Schmidt – Cassegrain and Maksutov – Cassegrain. Telescopes of the 1st subtype have a curvature in the center of the mirror diaphragm, which increases the field of view. Still, at the same time, spherical violations and deviations are excluded. Devices of subtype 2 have an optical lens in the focal plane area, which has a convexity on one side and a plane on the back, which makes it possible to compensate for the curvature of the field and avoid spherical deviation.

• Radio telescopes are designed for proper scientific research; instead of optical elements, special antennas capture space signals in a single frequency.

• Infrared – they perceive infrared radiation from objects. In other words, they react to heat, and they are more sensitive; the radiation is reflected on the objective lens and projected at one point, then the sensitive part converts the heat into visual data, and the result is photographed for further studies.

Telescopes differ from other optics in several ways. For instance, a telescope is an optical device with a single viewfinder that allows you to see and interpret distant objects, and binoculars, in their turn, have two viewfinders instead of one, and they are used to observe animals or are applied in hunting; it provides a three – dimensional image of the object as two eyes are used for observation. The difference is that binoculars have a smaller, less powerful wide lens, while the telescope has a more robust lens and a narrower field of view, which can be used for viewing farther distances. You can also compare telescopes and microscopes; the main difference between the two is that microscopes are used to magnify small objects at a short distance, while telescopes are used to magnify large objects at a great distance from us. Likewise, it is worth making it clear how a telescope differs from a spyglass. On the one hand, the spyglass has a lower magnification, a wider field of view, are compact and lightweight, and use prisms in their optical design to obtain a correctly oriented image. On the other hand, Telescopes give an inverted or mirror-symmetrical idea, which is not essential when observing the stars but may be completely inappropriate when tracking animals.

The primary purpose of this device is to collect as much radiation from celestial bodies as possible and to increase their illumination, which allows you to see even dim objects. The second important task assigned to telescopes is to create the sharpest possible image and, in visual observations, to increase the angular distances between objects (stars, galaxies, etc.). The amount of light a telescope can collect directly determines the detailing of the resulting image, from the lunar landscape to the rings of Saturn. This parameter does not depend on the telescope’s magnification, as many are accustomed to thinking, but directly depends on the lens, which collects the light rays; the objective can be either a lens or a mirror, which defines the base of the telescope.

Many of us are connoisseurs of beauty, so we want to learn more and more information about the thing that interests us. Watching the starry sky is an incredible process, which requires a telescope. This device will become your irreplaceable friend, allowing you to know more about space and its components – the stars.

Have you ever been mesmerized at least once in your life by the beauty and mystery of the night starry sky? Stars, planets, and satellites are massive cosmic bodies unique by their nature. All of them are unattainable in the physical sense for ordinary people like you and me. Space is a fantastic thing, which we can never touch with our hands; however, we can enjoy it from the side with the help of various complementary devices – the so-called telescopes.

The work of these devices consists of collecting electromagnetic radiation from distant objects. Nowadays, there are different telescopes: optical, radio telescopes, X-rays, and gamma telescopes. They all are differentiated by their mechanisms of work, appearance, etc. An important fact is that some of them are more difficult to apply and are intended for professional activities; others have the most necessary, so to speak, a standard set of functions to achieve the goal – viewing space objects and photographing them. Once all professionals were amateurs of their craft, learning astronomy with professional technology was a brutal and energy-consuming occupation. Therefore, the best seven telescopes for beginners are given below:

1.            Celestron StarSense Explorer – this telescope communicates with the device through the particular StarSense Explorer app so that you can view constellations and starspots. It is worth mentioning that the display is reproduced in real-time, and the sight on the screen turns green when a set goal is achieved. Wi-Fi and a cellular network are not necessary for use; in addition, there is a night mode when the screen turns red for better adaptation of the eyes in the dark. The lens is 130mm, and there are two available eyepieces: 1- 25 mm, which provides 26x magnification, and 2-10 mm, which provides 65x magnification. The device is accessible in applying and accurate in achieving the goal.

2.            Infinity Telescope Meade Instruments is a reasonably light refractory model with three eyepieces with several magnification options. The sight is established on a special fastening equipped with slow-motion control rods so that the target is not lost while tracking. The device is paired with the Windows AutoStar Suite Astronomer Edition integration software that helps you study the sky with over 10 000 celestial objects.

3.            Celestron PowerSeeker 127 EQ – the device is suitable for those who understand at least something in telescopes. A reasonably portable device, which is used for viewing in the countryside. The sight is established on a mount with a designated rod height for precise observation; two eyepieces have 50x and 250x magnification. There is a SkyX planetarium program with a database of 10 000 objects and print star charts.

4.            Gskyer EQ901000 Refracting Telescope – has a 70mm diaphragm and an easily accessible focus wheel. It is well suited for observing celestial objects as well as observing animals. The set includes three interchangeable eyepieces – 25mm, 10mm, and 5 mm, a scope for a finder, a tripod, a phone holder, and wireless remote control. The model has a long focal length and wide diaphragm for good focusing, reducing glare.

5.            The Orion StarSeeker IV – reflector model database contains over 42 000 targets. Has two eyepieces and a good lens, equipped with a moon filter. Eight AA-size batteries power it; however, it can be plugged into a wall outlet via an adapter or a portable generator. The telescope can likewise be controlled via Wi-Fi. The only drawback of the device is its weight in comparison with other models-this model is a bit heavier.

6.            Celestron NexStar 6SE Computerized Telescope – has a compact and portable form-factor, and along with this, is equipped with a large six-inch primary mirror. Combining these factors makes it quite robust and easy to assemble and disassemble. It is small in size but rather heavy in weight; with the help of adapters for the camera, astrophotography can be performed. Some additional functions can be purchased, like a SkyPortal Wi-Fi module, which provides wireless control and various new functions.

7. ToyBee 100246- a refractory telescope with three eyepieces. The telescope can be applied for viewing space objects and ground observation. It has a 70mm lens. In addition, the eyepiece has good characteristics, including 20mm: 15x; 6mm: 50x; and the focal length is estimated at 300mm.  The device does not require any additional tools.

Accordingly, we can conclude that such telescopes are tailored specifically for beginners. Developers make them high-quality for both the short and long term. Each of the above telescopes has essential functions, and some of them even have an additional role that improves the process and quality of viewing and photographing in general. If you have never done anything like this before, these are the models that will guide you on the path of knowledge of the starry sky.