It is enough to go to any specialized online store in Moscow and you will be provided with the necessary assortment. However, finding a reflecting telescope of guaranteed quality and at reasonable prices is not easy. We offer products of exclusively proven quality, the offered range and affordable prices are our competitive advantages and the main differences from other stores in this trade niche.

The larger the target, the larger the amount of light it will intercept, so that the formed images will have more detail and be brighter, so the diameter is very important, the larger diameter will not only capture more light, which will increase the power of the telescope by increasing, which he is able to withstand, and the strength of his resolution, which is the force with which he will have to separate two points, in short, to a larger diameter, obtaining more luminosity and fainter objects can be seen.

Of course, by this we do not mean that the magnification that a mirror of a given diameter can give us will be infinite, it has a limit. This is a purely theoretical value, then it should depend on where we installed the telescope, it will be the quality of the sky, which will decrease if we have a slight city parasite. How to create mirrors.

The cost of a reflecting telescope in our online store can become even lower for our regular customers. In addition, we often organize various promotions and provide good discounts on certain types of goods.

And if you find it difficult to independently choose the right device from the huge range presented in our online store, then you can seek advice from our specialists - professional managers who will be happy to tell you about all the pros and cons of the item you are interested in and help you choose exactly the right one. what you need at the most affordable price.

We have already advanced on the pages that precede some illustrations and brief comments on the mirrors that make up the optics of a reflecting telescope, in these lines we will give short review the materials to be used and how to accomplish this undertaking.

The good resolution of the images that you will see with your telescope, we must say, in essence, the maximum perfection that the optics of which it is composed have. We will try in this review on how to build reflector optics to satisfy the curiosity of those who are into simple telescope construction, or those who want to make optics in the future, to know that it can be done.

Reflector telescopes are most suitable for observing celestial objects; in reflectors, a system of mirrors is used as a light-collecting element, the main mirror of which is of two types: parabolic - a large lens diameter or spherical - a small lens diameter. The main advantage of the reflector is the absence of chromatic aberrations, which means a clear and bright visible image without distortion. However, it was not without drawbacks - reflectors are often large in size, there is a need for a rigid mount, and periodic adjustment of the mirror system is also necessary.

To create a reflective lens, two discs of regular green glass, which are commonly used for windows, etc. Of course, provided that its thickness is at least 20 mm, except for the so-called hardened, and which is free from internal stresses, to check that it does not have air bubbles visible to the naked eye, which will then cause a big headache in order to who cuts the mirror. But for a 150mm mirror. at 200 mm, excessive costs are not very justified. One of the glass disks will become a tool, and the other will become a future mirror.

A telescope is an astronomical optical instrument designed to observe celestial bodies.
The telescope has an eyepiece, a lens or a main mirror and a special tube that is attached to the mount, which, in turn, contains axes, due to which the pointing at the object of observation takes place.

In 1609, Galileo Galilei assembled the first optical telescope. (Read about it on our website: Who created the first telescope?).
Modern telescopes come in several types.

For example, the dimensions are 180 mm. Since this is a measure that will allow us to access a medium-sized telescope, it is easy to transport and receive a significant amount of light. Top left image: cut out the glass to get the two required surfaces. Right image. After the two surfaces have been cut, the excess glass is removed.

Left photo: as soon as the surface of the future optics is cut out. Right photo: Beveled edges with green Norton stone. To do the so-called mirror roughing, we will need different abrasives, from coarse to fine, and then finish polishing with cerium oxide or polishing red. Both emeralds and oxides should always be mixed with water for application. These products, such as carborundum, which come in the form of fine grains, have an extraordinary hardness, serve to eat glass and wear out.

Reflector (mirror) telescopes

If we give them the most simplified description, then these are devices that have a special concave mirror that collects light and focuses it. The advantages of such telescopes include ease of manufacture, good quality optics. The main disadvantage is a little more care and maintenance than other types of telescopes.
Well, now in more detail about reflector telescopes.
A reflector is a telescope with a mirror lens that forms an image by reflecting light from a mirrored surface. Reflectors are mainly used for sky photography, photoelectric and spectral studies, and they are used less often for visual observations.
Reflectors have some advantages over refractors (lens telescopes), because they do not have chromatic aberration (coloration of images); the main mirror is easier to make larger sizes than a lenticular lens. If the mirror is not spherical, but parabolic, then the spherical shape can be reduced to zero. aberration(blurring of the edges or middle of the image). The manufacture of mirrors is easier and cheaper than lens objectives, which makes it possible to increase the diameter of the objective, and hence the resolving power of the telescope. From a ready-made set of mirrors, amateur astronomers can create a homemade "Newtonian" reflector. The advantage due to which the system has gained popularity among amateurs is the ease of manufacturing mirrors (the main mirror in the case of small relative apertures is a sphere; a flat mirror can be small).

Depending on its thickness, we can get a surface that becomes progressively thinner and free of defects. Materials for grinding and polishing. Carborundum, emery, polisher, vegetable resin or resin with resin. Based on this, a mirror with a diameter of 180 mm will be cut.

May be imported or national, numbered as follows. Cerium oxide 200g. Cerium Oxide Alternatives: Zirconium Oxide, Blush Polishing. It is very difficult to obtain vegetable resin, it is possible that we are forced to use mineral resin, it is elastic, in order to avoid this, vegetable resins, castor oil or flax are added in the following proportions.

Newtonian reflector

It was invented in 1662. His telescope was the first mirror telescope. In reflectors, the large mirror is called the primary mirror. Photographic plates can be placed in the plane of the main mirror to photograph celestial objects.
In Newton's system, the lens is a concave parabolic mirror, from which the reflected rays are directed by a small flat mirror into an eyepiece located on the side of the tube.
Picture: Reflection of signals coming from different directions.

Castor oil is added to the resin at 10% before being mixed with the resin, that is, castor and resin are first mixed and then added to the resin. To determine the hardness of the tone, we bend the bar of the same, if when folded it returns to its place, it is that this one, too elastic, it does not help us, because it will spread if taken in a shape in this case, convex with plasticity on the surface of the tool. It is also necessary to have a certain hardness, so you work better.

Hardness is obtained by evaporating the solvents they contain when heated. It is convenient to mix hard pitch and soft resin in a harder amount. If we want to soften, add turpentine. Procedure for glass carving. The glass cutting procedure must be made on a work pole, which can be made using drop materials or using ingenuity, adapting any device that we have in the house and that serves to cover our need, it can be, for example, a bench, like those used by cartoonists, or any high and hard bench that we can put a good weight on to keep it from moving.

Gregory system reflector

Rays from the main concave parabolic mirror are directed to a small concave elliptical mirror, which reflects them into an eyepiece placed in the central hole of the main mirror. Since the elliptical mirror is located behind the focus of the main mirror, the image is upright, while in the Newtonian system it is inverted. The presence of a second mirror increases the focal length and thus enables a large magnification.

When we get to work with the mirror, we must bypass this post. Other friends used 200 liter barrels or drums with water inside, the way to do this is explained in How to Build Telescope Fans, where you will find a lot of material based on the ingenuity of builder friends.

After installing the bench, the tool disk is placed on the work surface and fixed with a blade so that it does not move, but not very tight, so that we can turn it when necessary. The surface on which we are going to do this work should be flat, placing a thin hard rubber to protect and work more comfortably.

Cassegrain reflector

Here the secondary mirror is hyperbolic. It is installed in front of the focus of the main mirror and allows you to make the reflector tube shorter. The main mirror is parabolic, there is no spherical aberration here, but there is a coma (the image of a point takes the form of an asymmetric scattering spot) - this limits the field of view of the reflector.

Then start using this tool with different abrasives as you progress from the thickest to the finest. Left image. How to observe the sanding work, with good lighting and if possible with a magnifying glass, in this way we can see if the shape of the work will go smoothly and if it will reach the edges. Right picture: two tools for measuring the arrow of a mirror, which has an exact curve, the other has a small ball made from a small pin, which exactly matches the size of the arrow we need to get.

Reflector of the Lomonosov-Herschel system

Here, unlike the Newtonian reflector, the main mirror is tilted so that the image is focused near the telescope's entrance hole, where the eyepiece is placed. This system made it possible to exclude intermediate mirrors and light losses in them.

Ritchey-Chrétien reflector

This system is an improved version of the Cassegrain system. The main mirror is a concave hyperbolic one, and the auxiliary mirror is a convex hyperbolic one. The eyepiece is installed in the central hole of the hyperbolic mirror.
Recently, this system has been widely used.
There are other reflex systems: Schwarzschild, Maksutov and Schmidt (mirror-lens systems), Mersen, Nessmit.

Top photo: how to use a tool that will measure the arrow while maintaining and observing with a light that allows us to see if it is fully supported or fully supported. The radius of curvature we get from a mirror will always be twice the focal length. We will need to create a support to support the singing of the mirror, which should be well rinsed with water, and be well wet, we put it on the stand. We moved a distance of about 4 meters, and with the burner lit we were reflected on the surface of the mirror.

Lack of reflectors

Their pipes are open to air currents that spoil the surface of the mirrors. From temperature fluctuations and mechanical loads, the shape of the mirrors slightly changes, and because of this, visibility worsens.
One of the largest reflectors is located in Mount Palomar astronomical observatory USA. Its mirror has a diameter of 5 m. The world's largest astronomical reflector (6 m) is located in the Special Astrophysical Observatory in the North Caucasus.

By moving the light point from left to right, we will see that the reflected image moves in the same direction, which indicates that we are not at the center of the curvature. Moving back, we will see how the image increases in size until the entire mirror remains as a luminous surface. This indicates that this point is approximately equal to the radius of curvature. You have to measure the distance between the surface of the mirror and the point of light, from left to right, inverse in the mirror, indicate that we have exceeded the radius, so we will have to go ahead.

Refractor telescope (lens telescope)

Refractors- These are telescopes that have a lens objective that forms an image of objects by refraction of light rays.
This is a classic long tube known to everyone in the form of a telescope with a large lens (objective) at one end and an eyepiece at the other. Refractors are used for visual, photographic, spectral and other observations.
Refractors are usually built according to the Kepler system. The angular vision of these telescopes is small, not exceeding 2º. The lens is usually two-lens.
Lenses in small refractor lenses are usually glued to reduce glare and light loss. The surfaces of the lenses are subjected to a special treatment (optical coating), as a result of which a thin transparent film is formed on the glass, which significantly reduces light loss due to reflection.
The world's largest refractor at the Yerkes Astronomical Observatory in the United States has a lens diameter of 1.02 m. A refractor with a lens diameter of 0.65 m is installed at the Pulkovo Observatory.

The calculation should be made as follows. Once the radius of curvature has been obtained and passed through the entire emery, which will allow us to go back to give the surface its original quality of brightness and smoothness, without wells or streaks, is a key task to complete the mirror. It will preferably be made of cerium oxide because the red polish is very good, but no one knows how to take it off because it stains a lot. Both grinding wheels and polishing rust dissolve in water for use.

Mirror-lens telescopes

A mirror-lens telescope is designed to photograph large areas of the sky. It was invented in 1929 by the German optician B. Schmidt. The main details here are a spherical mirror and a Schmidt correction plate installed in the center of the mirror's curvature. Due to this position of the correction plate, all beams of rays passing through it from different parts of the sky are equal in relation to the mirror, as a result of which the telescope is free from aberrations. optical systems. The spherical aberration of the mirror is corrected by a correction plate, the central part of which acts as a weak positive lens and the outer part as a weak negative lens. The focal surface, on which the image of a section of the sky is formed, has the shape of a sphere, the radius of curvature of which is equal to the focal length. The focal surface can be flattened using a Piazzi Smith lens.

To do the final job, we have to make a special "cake" of the optical pitch, of which we will need approximately 300 grams. Put it in a metal can, 300 grams of resin to take it to the fireplace to take Mary's bath, we put it on medium heat, it is gently heated until it is clean, without it boiling when it melted, we take it out of the fire, we mix it with a clean stick that does not give splinters, it tends to overflow in the center of the field, so we have to stir it.

disadvantage mirror-lens telescopes is a significant length of the tube, twice the focal length of the telescope. To eliminate this shortcoming, a number of modifications have been proposed, including the use of a second (additional) convex mirror, bringing the correction plate closer to the main mirror, etc.
The largest Schmidt telescopes are installed at the Tautenburg Astronomical Observatory in the GDR (D = 1.37m, A = 1:3), the Mount Palomar Astronomical Observatory in the USA (D = 1.22 m, A = 1:2.5) and at Byurakan Astrophysical Observatory of the Academy of Sciences of the Armenian SSR (D = 1.00 m, A = 1:2, 1:3).

Then, wait a little while not boiling, add 4 caps of refined castor oil, when we say four tapitas, take the cap of the oil bottle as a reference, mix well. Before starting this process, we must prepare the tool for the work pole, put a thick protective tape around it to make a protective edge, it will also be heated so that it will not be subjected to thermal shock when it is tipped over the same hot step. As soon as the field is poured onto the instrument, which is made from the center, there is a moment left, then the rest are placed in the center so that it is installed.

radio telescopes

They are used to study space objects in the radio range. The main elements of radio telescopes are receiving antenna and radiometer- sensitive radio receiver and receiving equipment. Since the radio range is much wider than the optical range, various designs of radio telescopes are used to detect radio emission, depending on the range.
When combined into a single network of several single telescopes located in different parts of the globe, one speaks of very long baseline radio interferometry (VLBI). An example of such a network is the American VLBA (Very Long Baseline Array) system. From 1997 to 2003, the Japanese orbiting radio telescope HALCA (Highly Advanced Laboratory for Communications and Astronomy), included in the network of VLBA telescopes, operated, which significantly improved the resolution of the entire network.
The Russian orbiting radio telescope Radioastron is planned to be used as one of the elements of the giant interferometer.

Touch the edge to see if it's there. Once the strip of paper is removed, a mirror is placed on top of it and cerium oxide is added. The edges are then pounded with a preheated knife to remove the excess that will remain on the edges by heating the knife in a flame and touching the edges to remove burrs.

Then we set the stride with mirror grease again with cerium and we see that it sits well. Usually the channels close during this operation, we have to re-mark them with a cutter or a razor blade as shown in the picture above. Once this is done, it will be polished with cerium dissolved in water, anointing the surface of the resin cake, and running the races just like roughing.

Space telescopes (astronomical satellites)

They are designed to carry out astronomical observations from space. The need for this type of observatory arose due to the fact that the earth's atmosphere delays the gamma, x-ray and ultraviolet radiation of space objects, as well as most of the infrared.
Space telescopes are equipped with devices for collecting and focusing radiation, as well as data conversion and transmission systems, an orientation system, and sometimes propulsion systems.

The job of creating a mirror takes about 30 hours, polishing alone takes 4 to 6 hours if it works properly. It makes more sense to take a notebook or folder of notes of the whole process as strictly as possible, this will help us in future projects, and also, if possible, take pictures of all important steps.

Once we have achieved that the entire surface of the mirror has been perfectly polished, we can control it. Then, when we want to get a parabolic shape, in order to achieve the highest optical accuracy, it will be necessary to take measurements with the Foucault apparatus.

X-ray telescopes

Designed to observe distant objects in the X-ray spectrum. To operate such telescopes, it is usually necessary to raise them above the Earth's atmosphere, which is opaque to x-rays. Therefore, telescopes are placed on high-altitude rockets or on artificial satellites Earth.

In the picture: X-ray Telescope - Position Sensitive (ART-P). It was created in the Department of High Energy Astrophysics of the Institute space research Academy of Sciences of the USSR (Moscow).