Holography
Also known as holography, it is an optically very tempting technology. We all have this experience. The oil film sprinkled on the road will show a variety of colors in the sun, and the same thing will be seen on the blown soap bubbles. The reason is that the reflected light from the two sides of the soap bubbles appears. Interference is called the thin film interference phenomenon of light. Light is the life of photography, and light has many characteristics, such as dispersion and scattering. Experienced photographers can make full use of these phenomena to turn harmful into beneficial, thereby adding some novel effects to the work. The camera lens is composed of multiple groups of lenses. In order to avoid the loss of light reflection on the lens surface, people invented lens coating technology to make the light of a certain wavelength cancel each other out when reflected, so as to increase the light entering the lens and make the image clearer. Similarly, people have used the interference characteristics of light waves to develop holographic photography technology with a three-dimensional effect. Holography was once a patented technology for scientists to conduct scientific research. Now ordinary people can master it after a certain amount of study. For example, counterfeit cards commonly used in credit cards or book covers are a three-dimensional imaging thing that can be seen in the sun. Displays colorful reflected light.
The word "holographic" may seem familiar to us, as it reminds us of the hologram of the human body in ear acupuncture. The human ear is a microcosm of the human body, which corresponds to various organs of the human body. From here, people have further studied that any part of the human body has information about the entire body, so it is called a hologram. Knowing this, it is easy to understand holography.
The difference between holography and ordinary photography
Category Holography General Photography
Recording method object beam light and reference beam optical lens imaging (object beam light) < /p>
Record the intensity and phase information of the light scattered by the content object, the scene itself or the intensity of the reflected light
After recording on the imaging medium, it is called a holographic film (full gray tone) photosensitive film
The image observation method generally relies on laser restoration to view directly with the viewing eye
Color expression color interference fringe image color object image
Image characteristics A three-dimensional scene with a three-dimensional space, only scattered light but no Image of a real plane object
1. What is the interference phenomenon of light
In the mechanics of physics class, we have done water wave interference experiments, and based on the wave characteristics of light, people have also successfully The interference and diffraction phenomena of light waves were observed. In order to obtain two light rays with the same frequency, let the light shoot from a slit to two small holes of the second screen at the same time. The two beams of light will appear interference fringes behind the screen. The appearance of the fringes is due to the peaks and troughs of the two beams of light. The light will be enhanced when superimposed (in phase), and weakened when they cancel each other out (antiphase). This phenomenon led Stephen Benton, a physicist at the Massachusetts Institute of Technology in the United States, to discover that there was a high technology hidden behind it, so he conducted further research on this technology
2. Characteristics of holographic images
p>The principle of holography was proposed by British physicist Dennis Gabor in 1947, for which the scientist himself won the Nobel Prize. When shooting a holographic image, the light wave itself and the relative phase of the two beams of light are recorded. The phase is caused by the position difference between the actual object (blue light in the picture) and the reference light (red light in the picture). From the holographic photo We cannot see the image of the object on the interference fringes. We must use a cohesive laser to accurately aim at the target and illuminate the hologram to reproduce all the information of the object light. A man named Banton later discovered a simpler method of using white light to restore images, thus bringing this technology to a practical stage. When the American "National Geographic Magazine" first used white light holograms on its cover, sales increased from 10 million copies to 16 million copies after the reprint. This technology was later spread from the United States to Europe and other countries, and is widely used in credit card and other counterfeiting technologies. Laser holography technology also became popular all over the world.
Holography is a type of photography that uses the interference of laser light waves to record images and reproduced images. It is completely different from the general stereoscopic photo technology. We can surround it and view all sides, but we can’t touch it. The significant features and advantages of real objects are as follows:
1. The reconstructed three-dimensional image is conducive to preserving precious artwork materials for collection.
2. Every point during shooting is recorded on any point of the hologram. It doesn’t matter if the photo is damaged.
3. Holographic photos have a strong three-dimensional effect and lifelike images. They can be displayed at various exhibitions with the help of lasers and will achieve very good results.