What is a Hologram?
A hologram is often described as a three-dimensional picture. While this is a good way to get a general idea of what you would experience looking at one, holography has very little in common with traditional photography. While a photograph has an actual physical image, a hologram contains information about the size, shape, brightness and contrast of the object being recorded. This information is stored in a very microscopic and complex pattern of interference. The interference pattern is made possible by the properties of light generated by a LASER. The light reflected by a three dimensional object forms a very complicated pattern that is also three dimensional. In order to record the whole pattern, the light used must be highly directional and must be of one color. Such light is called coherent. Because the light from a laser is one color, and leaves the laser with one wave in perfect step with all others, it is perfect for making holograms. When you shine a light on the hologram, the
– a hologram is the art of displaying a three-dimensional picture of an object on a two-dimensional carrier. It was invented in 1947 by Dennis Gabor who was awarded a Nobel Prize in physics in 1971. Holography allows a photograph to be displayed as a three-dimensional object. It takes two steps to create a hologram: (1) – The first step is the creation of the hologram through light reflection. (2) – The second step is to have the three-dimensional image become visible by light waves. It was not possible to create a hologram until the invention of the Laser (Light Amplification by Stimulated Emission of Radiation). The LASER provides the single beam light sources which enable us to create the hologram. How is the Hologram Created? – First we need a drawing, picture or a carved model. For example: the Rega issue used three components to form the hologram image. This is why it is referred to as a 2D/3D hologram. The 2D hologram components are: (1) Ambulance plane (Hawker 800 B) (2) Rotor
Holograms are photographic images that are three-dimensional and appear to have depth. Holograms work by creating an image composed of two superimposed 2-dimensional pictures of the same object seen from different reference points. Holography requires the use of light of a single exact wavelength, so lasers must be used. In reflection holograms, the kind of holography that can be viewed in normal light, two laser beams and a photographic plate are used to take an image of the object. Both laser beams used in a holograph go through beam spreaders, which spread the laser light out like a flashlight. The coherence of the beam is lost, but it remains an exact wavelength. One beam illuminates the object from the side. The other beam, known as a reference beam, travels through a photographic plate and hits the object head-on, similar to the way in which a conventional camera takes a 2-D image. The reflecting light from the reference beam leaves an image, or hologram, on the photographic plat
Well, a hologram is like a picture. Sort of. You see, when you look at a picture — like a photograph — it is flat. If you took a regular picture of a big marble, and it had a smaller marble behind it, you would not be able to look around the big marble to see the little one. With a HOLOGRAM, you would be able to look around the big marble and see the little one behind it. It’s true. That’s because a hologram is in 3-D. The letter “D” in “3-D” stands for the word “dimension”. The “3” in “3-D” stands for how many “dimensions” something has. A photo, a piece of paper — or even this computer screen — is 2-D, or two dimensions: up and down (1) and left and right (2). When something has 3-D, like the world in which we live — or a hologram — it has an added dimension: up and down (1), left and right (2) and forwards and backwards (3). When talking about dimensions, we call forwards and backwards “depth”. So . . . when we say that a hologram has 3 dimensions, it means we can see up and d
Holography is the process by which Three Dimensional Visual Information is Recorded, Stored and Replayed. A Hologram refers to the “Flat Picture” that displays a “Multi Dimensional Image” under proper illumination. Unlike any Photograph, a Holographic image has “Parallex” i.e. the Ability to be Seen from Many Angles and Depth – just like we see things in real life.
