1 first of all, let's understand the magnifying principle of the telescope. The calculation formula of telescope magnification is magnification = the focal length of objective divided by the focal length of eyepiece, which means that the greater the focal length of objective, the smaller the focal length of eyepiece and the greater the magnification. The galileo telescope I made here is that the convex lens is the objective lens and the concave lens is the eyepiece. In this way, what you see in the eyepiece is an upright enlarged image.

After preparing the objective lens and eyepiece, we will make the main body of the telescope. First, we must calculate the length of the telescope. The focal length of convex lens is 30cm, and that of concave lens is 5cm. Considering the telescope performance of the telescope, I finally determined that the shortest length of the telescope is 24.5cm and the longest is 35.5cm. According to this size, we use the waste paper box wallpaper knife belt as our telescopic telescope body. The two telescopic inlays must fit accurately, otherwise it will affect our experience.

3. Then there is the problem of lens. We cut a piece of cardboard into a square, dig a hole in the middle, fix the lens with double-sided tape, and then fix it on the fuselage with double-sided tape or adhesive tape, one in front of the other.

The definition of telescope depends on the quality of lens. It is generally believed that glass is more transparent than plastic, and the width of what you see depends on the diameter of the objective lens. The larger the diameter of the objective lens, the wider the field of view you can see.