You will need
  • — 2 lenses;
  • — heavy paper (Whatman or other);
  • epoxy or nitrocellulose adhesive;
  • — Matt black paint (e.g. enamel);
  • — wooden blank;
  • — polyethylene;
  • — Scotch;
  • — scissors, ruler, pencils, brushes.
Pick up lenses. Suitable spectacle glass that you can buy in an optical store. One of them should be from +4 to +6 diopters, the second from -18 to -21. The diameter of the positive lens is 4-5 cm, a negative 1-3 see
On a wooden cylindrical block, whose diameter is equal to the diameter of the negative lens, wrap 1 layer polietileno film and secure it with tape. You can take ordinary household package. On top of the film wrap paper tube, carefully promazyvaya each layer with glue. Pipe length shall be 126 mm. the Outer diameter equal to the diameter of the lens (positive). Remove the tube from the blank and allow to dry.
When the adhesive dries, the tube will harden - wrap it in one layer of polyethylene film and seal with tape. Exactly the same as in the previous step, wrap the tube with paper glue to wall thickness was 3-4 mm. the length of the outer pipe is also equal to 126 mm. Remove the outer part with the inner and allow to dry.
Remove polyethylene. Insert the inner tube in the outer. Less detail needs to go inside more with some friction. If there is no friction, increase the outer diameter of the smaller pipe with one or several layers of thin paper. Disconnect the pipes. Paint the inner surface black Matt paint. Dry these parts.
For the manufacture of the eyepiece glue 2 identical paper rings. This can be done on the same wooden disc. Outer diameter of rings equal to the inner diameter of the small pipe. The wall thickness is about 2 mm and a height of about 3 mm. Paint the ring black. Now made of black paper.
Assemble the eyepiece in the following sequence. The inner surface of the small pipe with one end grease glue an inch. Insert the first ring, then little lens. Put the second ring. Avoid getting glue on the lens.
While the eyepiece dries, make the lens. Make 2 paper rings. Their outer diameter should be equal to the diameter of the big lens. Take a sheet of thin cardboard. Cut out a circle with a diameter equal to the diameter of the lens. Inside the circle make a circular hole with a diameter of 2.5-3 cm. Glue the circle to the end of one of the rings. These rings are also vackraste black paint. Assemble the lens in exactly the same way as you collected the eyepiece. The only difference is that the first pipe is inserted into the ring glued to it with a circle, which should be facing the inside of the pipe. Hole plays the role of the diaphragm. Check the lens and a second ring. Let the design dry.
Insert ocular knee in the objective. Select a distant object. Move your tube to the sharp, pinching and spreading tube.