1. Select cylindrical or rectangular cans or cartons. Choose a clean container the size of a normal camera. For example, you can choose old paint cans, oatmeal packaging barrels, shoe boxes or coffee cans. Ensure that the top of the container can be sealed tightly.

2. Paint the inner and outer walls of the container black. You can also cover all containers with aluminum foil, but make sure there are no gaps. These cover packages are designed to prevent any light reflection inside the container.

3. Determine the size of the pinhole. The distance between the film and the pinhole will affect the shooting of photos. The position of the film is right against the pinhole, so if it is a can, the pinhole should be opened on the lid.

4. Punch a pinhole in the bottom of the jar. You can directly punch a hole in the can with a needle, or you can cut a square at the bottom, then punch a hole in the paper or foil with a needle, and then stick the paper or foil on the hole in the square. The second method generally works better, because you can wear a perfect circle, and you can start again if you fail.

5. Cut out the blinds with black cardboard. It is best to use thick opaque cardboard. Make sure the paper is thick enough so that it won't wrinkle when used.

6. Stick a less sticky tape on the other side of the cardboard (electrical tape works well, but it's too tight). When not taking pictures, stick this tape on the lower end of the cardboard to prevent external light from entering the camera.

7, cardboard to make a viewfinder, it is completed. The function of the viewfinder is to simulate the geometric relationship between the film and the pinhole, and the photographer can know what the photo looks like in the end through the viewfinder. )