How to use pinhole imaging to make a camera

How to do the small hole imaging experiment

1. Place the candle, small hole screen and ground glass screen. Light the candle and adjust the height of the candle and the screen so that the flame of the candle, the small hole and the center of the frosted glass screen are roughly in a straight line.

2. Move the position of the candle or frosted glass screen. You can see that the closer the candle is to the small hole or the farther the frosted glass screen is from the small hole, the larger the image will be.

3. The size of the small hole imaging is inverted.

Extended information:

1. "Small hole imaging" experimental conclusion:

1. Light propagates along a straight line in the same homogeneous material;

2. The closer the object distance is, the larger the image will be and the darker the brightness will be; the further the object distance will be, the smaller the image will be and the brighter the brightness will be.

2. Imaging principle

Light propagation in a straight line

Principle: Light travels in a straight line in the same homogeneous medium without being disturbed by gravity. Communication

3. Application:

1. Cameras and video cameras

Some cameras and video cameras use the principle of small hole imaging - the lens is a small hole ( Most of them install convex lenses to ensure the imaging distance of light). The scene enters the darkroom through a small hole, and the image is left on the film by some special chemicals (such as developer, etc.) (digital cameras, video cameras, etc. store the image through some photosensitive elements. in the memory card).

2. The wave theory of light

It plays a key role in the wave theory of light, such as Young's interference experiment, double slit experiment and other light interference experiments. Small hole imaging The principles and methods of interference experiments are still very useful in modern physics.

The principle of pinhole imaging is the linear propagation of light. The characteristics are: 1. The image is a real image. 2. The resulting image is inverted and centrally symmetrical with the original object. 3. The resulting image has the same size ratio as the object. 4. The ratio of the formed image to the size of the object is the distance from the aperture to the imaging screen divided by the distance from the aperture to the object. 5. The smaller the hole, the clearer the image, but the brightness will be smaller. 6. If the object is colored, the image is also colored, and the image is consistent with the color of the object. 7. The clarity of the image is related to the size of the hole and has nothing to do with the shape of the hole.

Use a plate with a small hole to block it between the wall and the object, and the reflection of the object will be formed on the wall. We call this phenomenon called hole imaging. By moving the middle plate back and forth, the size of the image on the wall will also change. This phenomenon illustrates the nature of light propagating in a straight line.

Some cameras and video cameras use the principle of small hole imaging - the lens is a small hole (most of them are equipped with convex lenses to ensure the imaging distance of light), and the scenery enters the darkroom through the small hole, as if it were absorbed by some special chemicals. Substances (such as silver halide, etc.) are left on the film (digital cameras, video cameras, etc. store images in memory cards through some photosensitive elements).

The conclusion obtained from the small hole imaging experiment is that light propagates along a straight line in the same homogeneous material. When the image distance remains constant, the closer the object distance is, the larger the image will be and the brightness will become brighter; the further the object distance is, the smaller the image will be and the brightness will become darker. When the object distance remains unchanged, the near image on the screen becomes smaller and brighter; the far image on the screen becomes larger and darker. When the positions of the object, hole, and screen remain unchanged, the imaging is premised. When the hole is relatively large, the image becomes brighter.

Can a camera be made based on the principle of pinhole imaging?

The principle of pinhole imaging is the linear propagation of light, resulting in an inverted real image

The imaging principle of a camera is the refraction of light (convex lens imaging), and the resulting image is an inverted, reduced real image

The two images are similar: both are inverted real images, and both can be adjusted by changing the object distance The size of the image

The difference: the former can be an image as large as the object, or even an enlarged image; the latter can only be a reduced image