The holographic projection technology of 20 14 Spring Festival Gala can be seen by the audience without any equipment (such as glasses)? How did you do that?

The first step is to record the light wave information of the object by using the interference principle, which is the shooting process: the subject.

Holographic projection shooting process

The object forms a diffuser beam under laser irradiation; The other part of the laser beam, as a reference beam, hits the holographic negative and interferes with the object light beam, converting the phase and amplitude of each point on the object light wave into spatially varying intensity, thus recording all the information of the object light wave by using the contrast and interval between interference fringes. Negative recording interference fringes become holograms, or holograms, after being developed and fixed.

The second step is to reproduce the light wave information of the object by using the diffraction principle, which is the imaging process: the hologram is like a complex grating. Under the irradiation of coherent laser, the diffracted light waves of linearly recorded sinusoidal holograms can generally give two images, namely the original image (also called the initial image) and the yoke image. The reproduced image has strong stereoscopic effect and real visual effect. Every part of the hologram records the light information of every point on the object, so in principle, every part of the hologram can reproduce the whole image of the original object. Through multiple exposures, multiple different images can be recorded on the same negative, and they can be displayed separately without interference.

Before 3D projection, the object should be photographed at 120. Readers who have seen 3D movies should know that if they take off 3D glasses, the picture will appear ghostly and blurred. This is because there is not one picture on the screen, but the superposition effect of two pictures from different angles.