Pseudo-Holography Screen Technologies
In this article I will show several ways to create pseudo-holographic images. "Pseudo" because the image is actually flat, but well-designed lighting and background create the illusion of volume.
The principle of operation is indicated in the following figure (in the diagram, the projector is located below, and in the video - above):
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As can be seen from the diagram, the observer does not see the projector lens; accordingly, it is rather difficult to understand how the image is formed.
The principle of the device film:
The film consists of an array of microprisms and microlenses. The prism redirects the beam of light, the lens defocus it in such a way that the output is a parallel beam of rays.
As you understand, where the lens / prism is, there are aberrations: this film (of any manufacturer) has a rather poor color rendition and small viewing angles at which there is no critical color distortion. For example, if you sit in front of this screen, the upper part will go into the blue range, and the lower part - into the red.
http://www.youtube.com/watch?v=zSxBW-rKmeY
C 2:24 appears Snoop Dogg (real).
This bearded technology was used as early as the 16th century ( proof on the wiki ), but with static images. Roxana Palmer made an excellent illustration of this method:
As the film is used Musion Eyeliner , other manufacturers, to be honest, I do not even know.
The principle of operation is similar to Pepper's ghost:
Production of this kind of products was also established in Russia, because the usual dubbing film with a specific reflection index is used as a special film.
The market also presents all sorts of variations on this topic:
http://www.youtube.com/watch?v=DTXO7KGHtjI
The principle of work to ugliness is simple.
The screen consists of a grid with a small cell, consisting of thin-thin woods. Thus, a person sees through the film, as well as the image on the film, formed by the projector and dispersed by the screen threads.
It is clear that such a screen should be observed from a decent distance so as not to distinguish between the cells and the screen threads.
The only drawback of this method is that the viewer through the screen sees the lens of the projector, which can blind. However, in concert halls the projector is perceived as one of the lighting devices.
With the help of ultrasonic generators from the water creates a fog, which is directed by an array of fans. The wall of fog disperses the radiation from the projector.
Live, of course, does not look as impressive as Pepper's ghost, but it has its own niche, which is confirmed by a couple of manufacturers of data screens.
The mirror rotates at a speed of 20 revolutions per second and reflects the image formed by the projector. For each rotation of the mirror at 1.25 degrees, the projector forms a new image, so a unique picture will be observed from any angle, creating the illusion of three-dimensional object.
This is probably the most real holographic image. The focused laser beam ionizes the gas, which in turn generates light at a given point.
Of course, commercial products are far away, but the technology is already impressive!
Pseudo-hologram based on translucent film
The principle of operation is indicated in the following figure (in the diagram, the projector is located below, and in the video - above):
')
- The projector shines on the film at a certain angle;
- The film redirects the flow of the projector to the viewer;
As can be seen from the diagram, the observer does not see the projector lens; accordingly, it is rather difficult to understand how the image is formed.
The principle of the device film:
The film consists of an array of microprisms and microlenses. The prism redirects the beam of light, the lens defocus it in such a way that the output is a parallel beam of rays.
As you understand, where the lens / prism is, there are aberrations: this film (of any manufacturer) has a rather poor color rendition and small viewing angles at which there is no critical color distortion. For example, if you sit in front of this screen, the upper part will go into the blue range, and the lower part - into the red.
Pepper's ghost
http://www.youtube.com/watch?v=zSxBW-rKmeY
C 2:24 appears Snoop Dogg (real).
This bearded technology was used as early as the 16th century ( proof on the wiki ), but with static images. Roxana Palmer made an excellent illustration of this method:
- A reflective screen is placed on the floor;
- A projector (or several projectors) is shining on top of the screen;
- Next to the screen is stretched a special translucent film;
- On the stage, all the lights are extinguished, only the minimum necessary to impart "depth" and accent lighting remains;
- The viewer sees the imaginary Tupac in the reflection in the film and, at the same time, the real Snoop Dogh through the film.
As the film is used Musion Eyeliner , other manufacturers, to be honest, I do not even know.
Virtual pyramid
The principle of operation is similar to Pepper's ghost:
- Specially prepared content is formed on the horizontal panel (the panel is located just below the eye level of the “average” viewer);
- The pyramid is made of glass / orstekla with a special film of the type Musion Eyeliner;
- The viewer observes the reflection of the image on the panel in the glass and, at the same time, the highlighted object inside the pyramid.
Production of this kind of products was also established in Russia, because the usual dubbing film with a specific reflection index is used as a special film.
The market also presents all sorts of variations on this topic:
Freeformat
http://www.youtube.com/watch?v=DTXO7KGHtjI
The principle of work to ugliness is simple.
The screen consists of a grid with a small cell, consisting of thin-thin woods. Thus, a person sees through the film, as well as the image on the film, formed by the projector and dispersed by the screen threads.
It is clear that such a screen should be observed from a decent distance so as not to distinguish between the cells and the screen threads.
The only drawback of this method is that the viewer through the screen sees the lens of the projector, which can blind. However, in concert halls the projector is perceived as one of the lighting devices.
Pseudo-holography on fog
With the help of ultrasonic generators from the water creates a fog, which is directed by an array of fans. The wall of fog disperses the radiation from the projector.
Live, of course, does not look as impressive as Pepper's ghost, but it has its own niche, which is confirmed by a couple of manufacturers of data screens.
Bonus Experimental methods
Based on rotating mirror
The mirror rotates at a speed of 20 revolutions per second and reflects the image formed by the projector. For each rotation of the mirror at 1.25 degrees, the projector forms a new image, so a unique picture will be observed from any angle, creating the illusion of three-dimensional object.
Laser hologram
This is probably the most real holographic image. The focused laser beam ionizes the gas, which in turn generates light at a given point.
Of course, commercial products are far away, but the technology is already impressive!
Source: https://habr.com/ru/post/158231/
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