How to make a simple astronomical telescope with a general magnifying glass

Although the aperture of ancient astronomical telescopes was small, the focal length was longer than that of magnifying glasses, and the grinding process was more precise.

Seeing galaxies is not a big deal. Find a clear night sky and go to the countryside away from the city where you can easily see the M31 galaxy with the naked eye. The reason why you can't see it is first of all a matter of weather and environment, and do you know which direction to look?

Homemade astronomical telescopes are generally to buy ready-made lenses, and you can go to ** to have a look. Of course, it's much more expensive than a magnifying glass.

First of all, it is really not possible to make your own telescope, there are many problems. For example, professional telescopes use double-cemented achromatic lenses, optical glass, etc., which are very different in use.

But ah, with regard to the question you asked: looking at the stars is about the same as seeing them with the naked eye -- that's so normal.

In fact, there have been several similar questions:

There are reminders here.

Truth be told, advertising in the field of astronomy seems to be a bit too much these days, and there are probably very few areas where the overall misleading propaganda is obvious to this extent - if you use the standards of other industries, it can be said that it is not the right thing - -

I've done this.

The objective lens can be made with a small magnifying glass with a clamping eye, the barrel can be processed with a can, the aluminum has good ductility, it is easier to connect, and the outside is reinforced with a wooden board.

The inside is covered with ink with long cardboard and lined with a roll of ink.

The magnification is about 30x, and it's best to get a tripod and see the lunar crater.

Two magnifying glasses are held up near and far away, and the effect of adding a concave lens behind the far one is better, but to be honest, the landlord gives up, the effect of doing it himself is not good, it takes half a day to get it out to see the moon or something, with this money, it is better to buy a pair of binoculars for hundreds of dollars to look comfortable! Yes, the landlord went buy a double-barrel

The tutorial of making a homemade high-powered astronomical telescope is as follows:

Equipment】 Yellow cardboard, convex lens.

Production] 1. Choose a convex lens with a focal length of 30 to 50 mm as an eyepiece, which can be replaced by a magnifying glass for repairing clocks. Use a convex lens with a focal length of about 1 meter as an objective, which can be replaced by 100-degree presbyoptic spectacle lenses.

2. Determine the focal length of the convex lens to determine the length of the lens barrel. Place the objective lens and eyepiece facing the sun respectively, put a piece of white cardboard on the other side of the lens, adjust the distance between the paper and the lens, so that the sun is clearly imaged on the white cardboard, and measure the distance between the lens and the paper with a ruler is the focal length of the lens.

3. The lens barrel is made of yellow board paper. The entire tube is divided into two sections: the objective tube and the eyepiece tube.

The diameter of the objective tube is approximately equal to the diameter of the objective lens and the length is approximately equal to the focal length of the objective. The outer diameter of the eyepiece tube is slightly smaller than the inner diameter of the objective tube, allowing the eyepiece barrel to be inserted into the objective tube and the focal length can be adjusted back and forth. The inner diameter of the eyepiece barrel is approximately equal to the diameter of the eyepiece lens and is 100 mm longer than the eyepiece focal length.

The barrel is made by cutting the yellow board paper into strips of paper 70 to 80 mm wide. Find a tube with a diameter equal to the diameter of the lens as the core. Wrap the yellow board paper strip around the core, one by one, without overlapping or gaping, and the two ends of the paper strip and the joint can be connected with glued kraft paper.

After the first layer is rolled, glue is applied to the outside of the yellow cardboard, and then the second layer is rolled in the opposite direction to the first layer.

After rolling, then apply glue and roll the third layer, the direction of winding is opposite to the second layer, generally three layers can be wound, the outermost layer of kraft paper is pasted, the core is removed, and it is placed vertically indoors to dry. After drying, the inner layer of the lens barrel is blackened with black ink to eliminate the influence of stray light on observation.

4. Install the lens in the lens barrel, so that the main optical axis of the objective lens and eyepiece is on the center line of the lens tube. The installation of the lens should be determined according to the size of the lens, the diameter of the lens is smaller than the inner diameter of the lens barrel can be installed according to Figure 19-4a, and the lens diameter is equal to the inner diameter of the lens barrel can be installed according to the way of b in the figure.

After the lens is installed, the eyepiece tube can be inserted into the objective lens barrel, aimed at the distant light with the eye, adjust the front and rear positions of the program lens and the objective lens, so that the distant light falls on the field of view seen by the telescope**, which indicates that the main optical axis of the eyepiece falls on the center line of the lens tube, otherwise the position of the eyepiece needs to be adjusted appropriately until it meets the requirements.

5) Install a bracket on the lens tube, which can be a movable tripod or another form, but it must make the lens barrel very stable when rotating. The bracket should be installed at the center of gravity of the telescope tube. There should be enough friction at the place of connection so that the telescope can stay in any position and be stable.

<>1. First of all, the objective lens, find a lens with a focal length of 80 cm, be sure to have a plano-convex lens, a suitable lens is generally between the aperture and the focal length ratio of 1:8 or 1:15, such as a lens with a diameter of 5 cm, press 1:

15 to calculate, 5x15 = 75 cm. If it is calculated according to 1:8, that is, 5x8 = 40 cm, which means that a lens with a diameter of 5 cm, the focal length between 40-80 cm is suitable, and the telescope imaging made is still good, and the telescope imaging made by too much is lower or more than this range will be very poor.

2. I use whiteboard paper (thick paper) to roll the outer cylinder of the lens, mainly to facilitate the installation of the objective tube, the thickness of the roll is determined by the inner diameter of the objective lens tube you have, and the diameter of the roll is just the hole in the objective tube. Roll the objective tube directly to the same diameter as the objective finch stalk.

3. Eyepiece, the focal length of about 3 cm can form a composite eyepiece with a focal length of about centimeter, if you want to achieve achromatic, the distance between the two lenses is two-thirds of the focal length of a single piece, and the focal length can be shortened to three-quarters of the original single focal length, and the magnification of the telescope is the focal length of the objective lens divided by the focal length of the eyepiece is equal to the magnification.

The steps are as follows:

1. Collect the required materials: a piece of corrugated cardboard of about 61 cm, a magnifying glass of the same size, super glue, scissors and a pencil.

2. Wrap a magnifying glass in a paper file, mark the diameter of the lower magnifying glass with a pencil on the paper and make sure the cardboard is tight.

3. Measure along the edge of the cardboard from the first mark, you need to measure 14 cm from the mark, and then glue the extra paper around the magnifying glass with glue.

4. Cut the other side of the marking line on the cardboard, along its width, the length of one side of the cardboard is about 224 cm.

5. Glue the first piece of cardboard around the magnifying glass, because the cardboard is about 14 cm away, so the edge of the cardboard also needs to be glued.

6. Make a second magnifying glass tube, this one is slightly larger than the first one, as long as the first one can just fit into the second one.

7. Put the first cylinder into the second cylinder of the first mill code to complete the production of the telescope.