Light experiment ① From pinhole camera to telescope
This experiment involves a pinhole camera, a camera, and a telescope. Students can see images that are only vaguely visible, and even farther away. You can experience the evolution of laboratory equipment. Please touch on the history of lens development and microscopes.
ウィキペディアより
Experiment 1: Let's make a pinhole camera
you need : different cylinder diameters two tracing paper (cylinder such as aluminum foil) Black drawing paper, convex (two things with different focal length) lens
As shown on the left, attach black drawing paper to the larger diameter and make a pinhole in the center. For those with a small diameter, attach a piece of paper that can be seen through from behind, such as tracing paper. If you stack these two tubes and look toward the bright window, you can see the outside scenery. This completes the camera obscura.
When the image is not visible: Make the holes in the color drawing paper a little larger. There will be more light and the image will be brighter. It will look blurry.
Experiment 2: Let's make a camera
Remove the large cylinder of black drawing paper and attach a convex lens.
Then, the convex lens collects the light and the outside scenery is much clearer. I am surprised at the difference from the camera obscura I mentioned earlier.
Experiment 3: Let's make a telescope
Next, remove the small tube of tracing paper and attach a convex lens to it as well. Make the cylinder movable. At this time, try to use a lens with the shortest focal length possible. In the case of the figure on the left, it will be 30/10 = 3 times. In this way, the magnification is determined in the form of division of the two focal lengths.
Experiment 4: Let's take a picture with a pinhole camera
Materials Cans such as cookies, aluminum cans, photographic paper, developer
図１ 図２ 図３
Make a hole in the cookie tin.
Cut an aluminum can into 2 x 3 cm pieces and open a pinhole (about 0.3 mm in diameter) in the center.
Attach an aluminum plate with a pinhole to the cookie can and fix the photographic paper inside the can.
Of course, when you tape the photographic paper, please do it in a dark room. Cover the area around the can with vinyl tape. Tape the pinholes as well. After that, just peel off the tape in front of the pinhole in front of what you want to copy.
Pinhole size
Can depth 4 cm or less Pinhole diameter 0.2 mm
Can depth 4-9 cm Pinhole diameter 0.3 mm
Can depth 9 cm or more Pinhole diameter 0.4 mm
If the size of the pinhole is too small, the light will be diffracted and the image will be distorted by the interfering light. Also, if it is too large, the light will spread and the image will be out of focus. You can also create various textures by intentionally blurring the image or by bending the photographic paper. The time to open the vinyl tape and expose it is very problematic. It is best to actually try it in 30 seconds on a sunny day and 2 minutes on a cloudy day.
