Small hole imaging law

1. As long as the hole is small enough, no matter what the shape of the hole is, it has little effect on the clarity and shape of the image.

2. The closer the image is to the hole, the smaller and brighter the image is; On the contrary, the bigger it is, the darker it is.

3. The closer the hole is to the candle, the bigger and darker the image; On the contrary, the smaller, the brighter.

4. In the pinhole imaging experiment, the image is an inverted real image, and the size and clarity of the image are related to the above conclusions.

Extended data

Natural applications:

1. The linear propagation characteristics of light in ancient astronomical calendars have been widely used in ancient astronomical calendars in China. Our ancestors made standard watches and sundials to measure the length and direction of the sun's shadow, so as to determine the time, winter solstice and summer solstice. Install peepholes on astronomical instruments to observe the sky and measure the positions of stars.

2. Some cameras and camcorders use the principle of pinhole imaging-the lens is pinhole (mostly equipped with convex lens to ensure the imaging distance of light), the scene enters the darkroom through pinhole, and the image is left on the film by some special chemicals (such as developer) (digital cameras and camcorders store the image in the memory card through some photosensitive elements).

Baidu encyclopedia-pinhole imaging