How to make a telescope yourself - a powerful homemade device like a Kepler reflector with your own hands. Newtonian telescope from what is at hand. Or how to make a telescope with your own hands How to make a telescope and its calculation
It is difficult to find a person on the whole earth who is not at least a little interested in astronomy. This, naturally, requires the presence of a certain instrument that would allow us to take a closer look at the mysteries of the starry sky. If you have a telescope or binoculars, then this is enough to admire the beauty of the starry sky. But even if there is strong interest, such devices cannot satisfy the request. Something more powerful is needed, that is, a telescope. But how to create it? Considering the question: “do it yourself?” and this article is dedicated to.
Introductory information
Purchasing a factory-made telescope will be quite expensive. Therefore, its purchase is appropriate in cases where there is a desire to engage in astronomy at least at an amateur level. But first, in order to gain basic knowledge and skills, and also to understand whether this science really seems like what most people think about it, it would be useful to create a homemade home telescope with your own hands. In many children's encyclopedias and various popular science publications you can find a description of the process of making a simple device that allows you to see craters on the Moon, the disk of Jupiter along with its four satellites, the rings and Saturn itself, the crescent of Venus, individual bright and large star clusters and nebulae. It should be noted that weak point Such devices have an image quality that cannot compete with factory-made devices.
A little theory
Before you start creating a telescope with your own hands at home, it’s worth understanding how this device works.
The two minimum required optical components are a lens and an eyepiece. The first one is designed to collect light. Its diameter determines what maximum magnification the finished device will have, and how faintly visible objects can be observed. An eyepiece is needed to magnify the image that is formed by the lens and to transmit the image to the human eye.
Deciding on the type
Depending on the device, there are different telescopes. The two most common types are reflectors and refractors. In the first case, a mirror acts as a lens, in the second, a lens system. At home, creating everything in the required quality for a reflector is quite problematic, due to the difficulty and precision of the manufacturing process. Whereas refractor lenses are easy to purchase at an optical store. As you can see, the difference between them is purely in design.
First try
The ratio of the focal length from the lens to the eyepiece is used to determine the magnification value. The scheme discussed below will provide an improvement in visual properties by approximately 50 times.
Initially, you need to stock up on a blank lens for glasses, the power of which is one diopter. This corresponds to a focal length of one meter. Usually their diameter is about 7 centimeters. This is exactly what is needed for the lens. It should be noted here that if you are interested in how to make a telescope with your own hands from glasses lenses, then you should admit that they are poorly suited for such non-targeted use. But you can use them if you wish. If you have a long-focus biconvex lens, then it is better to use it. Although it is still suitable for the role of an eyepiece magnifying glass from a magnifying glass with a diameter of 3 centimeters or a lens from a microscope.
For the body, you need to make two pipes from thick paper. The first (representing the main part) will be one meter long. A twenty-centimeter pipe is created for the eyepiece assembly. The short one is inserted into the long one. To make the body, you can use a wide sheet of whatman paper or a roll of wallpaper, rolling them into a pipe in several layers and gluing them with PVA. The number of layers is selected manually. It is necessary to achieve the effect of rigidity of the future device. In this case, the internal diameter of the main part must be equal to the size of the selected lens.
But that's not all
If the only question is how to make a telescope with your own hands at home, then you can get by exclusively with the above.
But for best result You can’t do without some nuances.
So, the lens must be mounted in the first pipe with the convex side outward using a frame. For this purpose, rings of comparable diameter and a thickness of a centimeter are suitable. Immediately after the lens, you need to install a disk - the diaphragm. Its specific difference is the presence in the center of a hole with a diameter of 2.5-3 centimeters. This must be done to reduce image distortion that is formed by a single lens. True, this approach reduces the amount of light that the lens collects. To improve the result, the lens should be installed as close to the edge of the pipe as possible. Then it’s the turn of the eyepiece. Where should I place it? It must be installed in the eyepiece assembly as close to the edge as possible. In this case, a cardboard mount would be ideal for the eyepiece. It is better to make the device in the form of a cylinder, the diameter of which is equal to the size of the selected lens. It is installed inside the pipe thanks to two fasteners (for example, disks). In this case, it is necessary to ensure that its diameter is commensurate with both the lens and the eyepiece unit.
Preparing the Telescope for Use
The device is focused by changing the distance between the lens and the eyepiece. This is achieved, in a mechanical sense, by ensuring the movement of the eyepiece unit located in the main tube. To fix the position, it is best to use friction. It should be noted that it is more convenient to focus on large and bright objects, such as nearby buildings, the Moon, bright stars (but not the Sun).
When creating a telescope, it should be taken into account that the lens and eyepiece should be parallel to each other, and their centers should be located on the same line. During the preparation stage, you can experiment with the diameter of the aperture hole in order to find the optimal one. For example, if you select a lens of 0.6 diopters and set the focal length to 1.7 meters (1/0.6), this will allow you to achieve greater magnification. True, you will have to work on the aperture hole. Namely, increase its size.
And after completing work on the first device, remember one simple truth: through a telescope you can look at the Sun only twice - first with your right eye, then with your left. Such a dangerous activity instantly damages your eyesight, so it is better not to engage in it.
Subtotal
It should be noted that the resulting design will be imperfect. Namely, it will give an inverted image. To correct this, it is necessary to use another converging lens, with the same focal length as the eyepiece. It is installed in a pipe near it. It would seem that now there should be no questions about how to make a telescope with your own hands with magnification. But this is far from the only correct approach.
You can use other schematic options, using glasses or telephoto lenses as a basis. This is a very broad field in which there are both completely green beginners and professional astronomers. Therefore, if a certain question or misunderstanding of something arises, do not be shy, calmly ask the question of interest. For this purpose today there are thematic circles, websites, forums, etc. After all, you just have to plunge into the world of astronomy - and numerous treasures of the starry sky will open to your eyes. In general, the practical information considered should be enough to create a simple device. If you want to design and implement something more complex, then you cannot do without high-quality theoretical training.
Required knowledge
You should always remember that the main characteristics are the size of the lens, eyepiece and focal length. This is alpha and omega, without which it is impossible to create a telescope. But at the same time there is a large number of small moments that can significantly affect the final result. For example, the maximum usable magnification of a telescope. The value of this parameter is equal to twice the lens diameter (in millimeters). It makes no sense to make a device with high magnification, since, most likely, you will not be able to see new details. But the overall brightness of the image will suffer. Therefore, for devices with a fifty-fold magnification, it is not recommended to use lenses less than 2.5 centimeters. It should be noted that the option proposed above has indicators of 7 and 3 cm, which is well suited for a telescope with a quality of 50x. You can take a 4-cm lens as a lens, but in this case the resolution will decrease optical device. Therefore, it is better to use the recommended values.
Experimenting with design
The option when a main pipe of one meter is created and an additional one of twenty centimeters is built into it is not all. The design can be adjusted to create other forms of telescopes. For example, a tube of 60-65 centimeters is used for the lens, and another one enters it at 10-15 cm for the eyepiece, the length of which is 50-55 cm.
Back to theory
Minimum value useful increase for a telescope depends on the diameter of the eyepiece. There is one very important nuance! Its size should not exceed the diameter of the observer's fully dilated pupil. Otherwise not all collected by telescope light will enter the eye: it will be lost, deteriorating the quality of the device. So, the maximum diameter of the pupil of the eye is ordinary person does not exceed five to seven millimeters. Therefore, to find the minimum useful magnification, take 10x (aperture multiplied by 0.15). This interesting word, aperture, means an opening similar to a diaphragm, only somewhat refined and advanced. This device is used in complex devices to obtain high-quality results. But this is for those who want to make a telescope with their own hands at home with serious characteristics for a more thorough study of the starry sky.
Conclusion
Well, that’s the minimum that everyone needs to know in order to create their own device for studying the starry sky. It doesn’t matter what the first step is - you assemble a reflector telescope with your own hands or a refractor. The main thing is that if this is of interest, then you need to act in this direction - study, master new knowledge, practice, discover something new for yourself or even for the whole world - do not stop, and luck favors those who are purposeful.
But be aware that when making devices with higher magnification, diffraction phenomena will become more pronounced. This will lead to poor visibility. And finally, the task: what basic parameters should a telescope providing 1,000x magnification have?
So, you have decided to make a telescope and are getting down to business. First of all, you will learn that the simplest telescope consists of two biconvex lenses - the objective and the eyepiece, and that the magnification of the telescope is obtained by the formula K = F / f (the ratio of the focal lengths of the lens (F) and the eyepiece (f)).
Armed with this knowledge, you go digging through boxes of different junk, in the attic, in the garage, in the shed, etc. with a clearly defined goal - to find more different lenses. These can be glasses from glasses (preferably round ones), watch magnifiers, lenses from old cameras, etc. Having collected a supply of lenses, start measuring. You need to choose a lens with a larger focal length F and an eyepiece with a smaller focal length f.
Measuring focal length is very simple. The lens is directed at some light source (a light bulb in the room, a lantern on the street, the sun in the sky or just a lit window), a white screen is placed behind the lens (a sheet of paper is possible, but cardboard is better) and moves relative to the lens until It will not produce a sharp image of the observed light source (inverted and reduced). After this, all that remains is to measure the distance from the lens to the screen with a ruler. This is the focal length. You are unlikely to cope with the described measurement procedure alone - you will need a third hand. You'll have to call an assistant for help.
Once you have selected your lens and eyepiece, you begin constructing the optical system for magnifying the image. You take the lens in one hand, the eyepiece in the other, and through both lenses you look at some distant object (not the sun - you can easily be left without an eye!). By mutually moving the lens and eyepiece (trying to keep their axes on the same line), you achieve a clear image.
The resulting image will be enlarged, but still upside down. What you are now holding in your hands, trying to maintain the achieved relative position of the lenses, is the desired optical system. All that remains is to fix this system, for example, by placing it inside a pipe. This will be the spyglass.
But don't rush into assembly. Having made a telescope, you will not be satisfied with the image “upside down”. This problem is solved simply by a wrapping system obtained by adding one or two lenses identical to the eyepiece.
You can obtain a wraparound system with one coaxial additional lens by placing it at a distance of approximately 2f from the eyepiece (the distance is determined by selection).
It is interesting to note that with this version of the reversing system, it is possible to obtain greater magnification by smoothly moving the additional lens away from the eyepiece. However, you won’t be able to get a strong magnification if you don’t have a very high-quality lens (for example, glass from glasses). The larger the lens diameter, the greater the magnification obtained.
This problem is solved in “purchased” optics by composing a lens from several lenses with different refractive indices. But you don’t care about these details: your task is to understand the circuit diagram of the device and build the simplest working model according to this scheme (without spending a penny).
You can obtain a wraparound system with two coaxial additional lenses by positioning them so that the eyepiece and these two lenses are spaced from each other at equal distances f.
Now you have an idea of the telescope design and know the focal lengths of the lenses, so you begin to assemble the optical device.
Well suited for assembling PVC pipes of various diameters. Scraps can be collected at any plumbing workshop. If the lenses do not fit the diameter of the tube (smaller), the size can be adjusted by cutting rings from a tube close to the size of the lens. The ring is cut in one place and put on the lens, secured tightly with electrical tape and wrapped. The tubes themselves are adjusted in the same way if the lens is larger than the diameter of the tube. Using this method of assembly you will get a telescopic telescope. It is convenient to adjust magnification and sharpness by moving the device sleeves. Achieve greater magnification and image quality by moving the wrapping system and focusing by moving the eyepiece.
The process of making, assembling and customizing is very exciting.
Below is my telescope with 80x magnification - almost like a telescope.
Many people, looking up at the starry sky, admire the alluring mystery of outer space. I want to look into the endless expanses of the universe. See craters on the moon. Rings of Saturn. Many nebulae and constellations. So today I will tell you how to make a telescope at home.
First, you need to decide how much magnification is required. The fact is that the larger this value, the longer the telescope itself will be. At 50x magnification the length will be 1 meter, and at 100x magnification it will be 2 meters. That is, the length of the telescope will be directly proportional to the magnification.
Let's say it will be a 50x telescope. Next, you need to purchase two lenses at any optics store (or on the market). One for the eyepiece (+2)-(+5) dioptres. The second is for the lens (+1) diopter (for a 100x telescope, (+0.5) diopter is required).
Then, taking into account the diameters of the lenses, it is necessary to make a pipe, or rather two pipes - one should fit tightly into the other. Moreover, the length of the resulting structure (in the extended state) should be equal to the focal length of the lens. In our case, 1 meter (for a lens (+1) diopter).
How to make pipes? To do this, you need to wrap several layers of paper on a frame of the appropriate diameter, coating them with epoxy resin (you can use other glue, but the last layers are better strengthened with epoxy). You can use the remnants of wallpaper that are lying around idle after renovating your apartment. You can experiment with fiberglass, then it will be a more serious design.
Next, we build the objective lens (+1) diopter into the outer tube, and (+3) diopter into the inner eyepiece. How to do it? Your imagination is the main thing to ensure precise parallelism and alignment of the lenses. In this case, it is necessary to ensure that the distance between the lenses when moving the pipes apart is within the focal length of the objective lens, in our case it is 1 meter. In the future, by changing this parameter, we will adjust the sharpness of our image.
For convenient use of the telescope, a tripod is needed to clearly fix it. At high magnification, the slightest trembling of the tube leads to blurring of the image.
If you have any lenses, you can find out their focal length in the following way: focus sunlight onto a flat surface until you get the smallest point possible. The distance between the lens and the surface is the focal length.
So, to achieve a telescope magnification of 50 times, it is necessary to place a lens of (+1) diopter at a distance of 1 meter from the lens of (+3) diopter.
For 100x magnification, we use lenses (+0.5) and (+3) changing the distance between them by 2 meters.
And this video shows the process of creating a similar telescope:
Enjoy your astronomical viewing!
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The times when anyone could make a discovery in science are almost completely gone. Everything that an amateur can discover in chemistry, physics, biology has long been known, rewritten and calculated. Astronomy is an exception to this rule. After all, this is the science of space, an indescribably vast space in which it is impossible to study everything, and even not far from the Earth there are still undiscovered objects. However, in order to practice astronomy, you need an expensive optical instrument. Is a homemade telescope a simple or difficult task?
Maybe binoculars would help?
It is too early for a novice astronomer who is just beginning to take a closer look at the starry sky to make a telescope with his own hands. The scheme may seem too complicated for him. At first, you can get by with ordinary binoculars.
This is not as frivolous a device as it might seem, and there are astronomers who continue to use it even after becoming famous: for example, the Japanese astronomer Hyakutake, the discoverer of the comet named after him, became famous precisely for his addiction to powerful binoculars.
For the first steps of a novice astronomer - in order to understand whether this is mine or not - any powerful marine binoculars will do. The bigger, the better. With binoculars you can observe the Moon (in quite impressive detail), see the disks of nearby planets, such as Venus, Mars or Jupiter, and examine comets and double stars.
No, it's still a telescope!
If you are serious about astronomy and still want to make a telescope yourself, the design you choose may belong to one of two main categories: refractors (they use only lenses) and reflectors (they use lenses and mirrors).
Refractors are recommended for beginners: these are less powerful telescopes, but easier to make. Then, when you gain experience in making refractors, you can try to assemble a reflector - powerful telescope with your own hands.
What makes a powerful telescope different?
What a stupid question, you ask. Of course - by magnification! And you will be wrong. The fact is that not all celestial bodies can, in principle, be enlarged. For example, you will not magnify the stars in any way: they are located at a distance of many parsecs, and from such a distance they turn into practically points. No approach is enough to see the disk of a distant star. You can only “zoom in” on objects in the solar system.
And the telescope, first of all, makes the stars brighter. And this property is responsible for its first most important characteristic - the diameter of the lens. How many times is the lens wider than the pupil? human eye- all the luminaries become so many times brighter. If you want to make a powerful telescope with your own hands, you will have to look, first of all, for a very large diameter lens for the objective.
The simplest diagram of a refracting telescope
In its simplest form, a refracting telescope consists of two convex (magnifying) lenses. The first - the large one, aimed at the sky - is called the lens, and the second - the small one, into which the astronomer looks, is called the eyepiece. You should make a homemade telescope with your own hands exactly according to this scheme if this is your first experience.
The telescope lens must have optical power one diopter and the largest possible diameter. You can find a similar lens, for example, in a glasses workshop, where glasses for glasses are cut out of them. various shapes. It is better if the lens is biconvex. If you can’t find a biconvex lens, you can use a pair of plano-convex half-diopter lenses, located one after the other, with convex points at different sides, at a distance of 3 centimeters from each other.
Any strong magnifying lens will work best as an eyepiece, ideally a magnifying glass in an eyepiece on a handle, such as those that were produced before. An eyepiece from any factory-made optical instrument (binoculars, geodetic instrument) will also work.
To find out what magnification the telescope will provide, measure the focal length of the eyepiece in centimeters. Then divide 100 cm (the focal length of a lens of 1 diopter, that is, a lens) by this figure, and get the desired magnification.
Secure the lenses in any durable tube (cardboard, coated with glue and painted on the inside with the blackest paint you can find will do). The eyepiece should be able to slide back and forth within a few centimeters; this is necessary for sharpening.
The telescope should be mounted on a wooden tripod called a Dobsonian mount. A drawing of it can be easily found in any search engine. This is the easiest to manufacture and at the same time reliable mount for a telescope; almost all homemade telescopes use it.
I always wanted to have a telescope to observe starry sky. Below is a translated article by an author from Brazil who was able to make a mirror telescope with his own hands and from available materials. Saving a lot of money at the same time.
Everyone loves to look at the stars and look at the moon in the clear night. But sometimes we want to see far. We want to see him nearby. Then humanity created a telescope!
Today
We have many types of telescopes, including the classical refractor and the Newtonian reflector. Here in Brazil, where I live, the telescope is a luxury. It costs between R$1,500.00 (about US$170.00) and R$7,500.00 (US$2,500.00). It's easy to find a refractor for R$500.00, but this is close 5/8 wages, considering that we have many poor families and young people waiting better life state. I'm one of them. Then I found a way to look at the sky! Why don't we make our own telescope?
Another problem here in Brazil is that we have very little content about telescopes.
Mirrors
and the lens is not particularly expensive. So, we do not have conditions for purchasing later. An easy way to do this is by using things that are no longer useful!
But where to find these things? Easily! The reflector telescope is made from:
— Primary mirror (concave)
— Secondary mirror (plan)
— Optical lens(the hardest part!)
— Adjustable plug.
— Tripod;
Where can I find these things?
— Concave mirrors are used in beauty salons (makeup, shops, hairdresser, etc.);
— Flat mirrors are found in many things. You just need to find a small mirror (about 4 cm2);
— The optical lens is hardier to find. You can get it from a broken toy or make it yourself. (I used an old 10x lens from a broken pair of binoculars).
- You can use water pipes (something between 80mm and 150mm in diameter), but I use empty ink tin and towel tin.
- Some black splashes.
You
You need PVC pipes, connectors and a few cardboard rolls too.
You can use hot glue or silicone paste.
So, no more waiting! Let's get it started!
Step 1: Calculation of optical components
I get 140mm Diameter of the concave mirror from Sagit from 3.18mm (measured with a caliper).
But first you should know that the mirror is Sagitta. In the depth of the mirror (the distance between the lowest part of the surface and the height of the boundaries).
Knowing this, we have:
Mirror radius (R) = d/2 = 70 mm
Radius of curvature (P) = P2 / 2C = 770.4 mm
Focal length (F) = p/2 = 385.2 mm
Aperture (F) = F / d = 2.8
Now we know everything we need to make our telescope!
Let's start!
Step 2: designing the main tube
By a strange coincidence, our paints are perfect for tin towels!
First we need to remove the paint on the bottom; we can’t.
Then you need to measure the distance between the concave mirror and the eyepiece location. To do this, you need to take into account the radius of the spray paint.
We then mark the height at 315mm. This is about 30 cm.
At this height, we make a hole in the can, as in the photo. In this case, I made a hole about 1.4 inches to fit the PVC connector.
As you can see in the next photo, the mirror fits perfectly into the can.
Step 3: Flat Mounting
I decided to fix it to support the mirror through 3 points, as in the drawing.
To fit the mirror plane, I used two wooden sticks and a small wooden triangle with a 45° angle.
Then I made some arrangements. With a drill, I made holes to insert the sticks.
Then I calculated the distance between the center of the mirror and the handle of the hole. This is 20 mm.
Make holes in the paint can with a drill.
So I adjusted the sticks to the plane of the mirror, when the eye holes are observed, my own eyes show.
*I attached the mirror in support with hot glue.
Step 4: Focus Adjustments
I used the microphone pedestal as a telescope tripod. Fitted with tape and elastic.
To find the hearth, we must aim for the sun with a telescope. Obviously, never look at the sun through a telescope!
Place the paper in front of the eye hole and find a smaller light spot. Then measure the distance between the hole and the paper as shown in the picture. Me from a distance of 6 cm.
This distance is required between the hole and the eyepiece. To fit the eyepiece I used a cardboard roll (from toilet paper), cut up and fixed with a little tape.
Step 5: Support & Dress
Important detail:
Anything inside the pipe should be black. This prevents light from reflecting in other directions.
I drew ink on the outside of the black tin only on appearance. I also drove pins to hold the tin towels better in the tin paint.
Some other barretes hold better secondary mirror sticks... and then I fixed the "PVC tripod socket" with a rivet and hot glue.
I added a gold plastic edge to the top of the tin ink to make it look nice.
Step 6: Tests and Final Considerations
I waited for the dark like a child waits for a Christmas present. Then night came and I went outside to check my telescope. And here is the result:
As we know, it is very difficult to take photographs with a telescope.
But, as you can see, it works!
A very important book to help with this project was:
NICOLINI, Jean. "The management is not Astronomo Amador." Papyrus, 2nd ed., 1991.
I need to wait for the moonlight because we are in New Moon. Then I'll try to take a picture of the Moon.
Thank you for your attention.