Holograms: Images of the Future
Faced with a growing number of fake credit cards, Visa and Mastercard in the early eighties decided to print holograms of their individual seals on the credit cards. When there was an alarming increase in fake driver's licences, the California Department of Motor Vehicles incorporated a hologram of the seal of the State on all driver's licences. Scientists at several laboratories are using holograms to improve imaging of cells and tissues of plants and other biological systems. Rock videos are now routinely produced with amazingly real graphics, thanks to advances in holography and computer generated graphics. These are but some of the examples of how holograms, or "3-D pictures" are revolutionizing several areas of technology.
In 1947, a Hungarian born physicist, Dennis Gabor, working at the Imperial College of Science and Technology in London, discovered a technique for photography, which had the potential for 3- dimensional effects. In the next few years not only did he develop the technique systematically, (including its use in his field of interest namely electron microscopy) but also coined the word hologram from the Greek holos (whole) and gramma (a letter). Though a lot of work on holography went on in the West and in the erstwhile Soviet Union, the technology needed for the production of quality holograms was not available and so the interest in holography was restricted to scientific laboratories.
All this changed in the sixties with the invention of the other landmark technology of the late twentieth century: Lasers. Laser light has certain remarkable properties which make it indispensable for producing holograms. It is exceptionally monochromatic i.e a red laser beam has only red light as opposed to ordinary red light which is a mixture of several colors with red dominating. It is very coherent and can be transmitted over great distances without the beam spreading. In fact, in a now classic experiment, lasers were used to find out the distance to the moon because a laser beam from earth can travel all the way to the moon without any appreciable spreading, and then be reflected back!
Holography, photography by wave front reconstruction, lens less photography; all these synonyms capture only a part of the "depth" of this fascinating technology. It is similar to ordinary photography and yet fundamentally different from it. In photographing an object, light from the object is captured by the camera lens and focussed onto a recording media, usually a film of some kind.
In 1895, Professor Wilhelm C. Roentgen, a German physicist, was working with a cathode ray tube, much like our fluorescent light bulb. The tube consisted of positive and negative electrodes encapsulated in a glass envelope. On November 8, 1895, Roentgen was conducting experiments in his lab on the effects of cathode rays. He evacuated all the air from the tube and passed a high electric voltage through it after filling it with a special gas. When he did this, the tube began to give off a fluorescent glow. Roentgen then shielded the tube with heavy black paper and discovered a green colored fluorescent light could be seen coming from a screen located a few feet away from the tube.
Prior to the invention of the daguerreotype, the Camera Obscura was the main optical instrument that was used to project images onto paper. The Camera Obscura was a device in the shape of a box that allowed light, which was being reflected from the images that the user was intending to capture, to enter through an opening at one end of the box to form an image on a surface and an artist would then trace the image to form the most accurate impression of an image at that peri...
The camera obscura was “is an optical device that projects an image of its surroundings on a screen. It is used in drawing and for entertainment, and was one of the inventions that led to photography. The device consists of a box or room with a hole in one side. Light from an external scene passes through the hole and strikes a surface inside where it is reproduced, upside-down, but with colour and perspective preserved. The image can be projected onto paper, and can then be...
Film cameras have been in the process of developing since 1664-1666 when Sir Issac Newton discovered light is composed of different colours and in 1724 when Johann Heinrich Schulze discovered that silver nitrate darkened upon exposure. It was in 1814 when Joseph Neipce achieved the world’s first photographic image after eight hours of light exposure. As technology developed through the years, more advancement has been made to film photography thus gradually changing the way film cameras operate. When a camera records an image, it’s recording the visible light (or flash) reflecting off the objects in the camera’s view. The reflect light causes a chemical change in photographic film (chemical records. Light has its own color spectrum, the electro-magnetic spectrum where the primary colours are RGB (Red Green Blue). Packets of energy traveling via light are called photons. The amount of energy determines the length of the wave lengths of the colours, which in turn determines the colour. The energy in photons creates a chemical change in the photographic detectors th...
Following the analysis on the history of the pinhole technique, the next step is to understand the description of a pinhole camera. David Balihar refers to a pinhole camera as a simple optical imaging device in the shape of a closed box or chamber (Balihar 2013). The pinhole camera is different from most photographic devices, in the sense that it does use a lens. Furthermore, a pinhole camera has an infinite depth of field. To explain further, most cameras have a limited depth of field and must be adjusted for an object to come into focus. With a pinhole camera, all objects in the field of view are in focus no matter how far there distance is. As stated previously, this is be...
The first models of the Camera Obscura were large chambers that could be entered by the artist. At first, this invention was recognized as an aid to artists who could trace the images to create a more realistic impression of the scene. The difficulty with the chamber was that it was not readily portable, and was therefore useless to an artist. This issue was solved when advancements were made in the seventeenth century when inventors developed a portable version of the optical device. Also, those using the instrument found that the image produced was inaccurate in that it defied the rules of perspective because it was formed by a single lens. Inventors discovered a way to correct this problem, as explained in the History of Photography:
A common misconception is that virtual reality is just for entertainment. As we contemplate about some of the technology involved in virtual reality, entertainment is generally the first thing a lot of people think of when virtual reality springs to mind, but here we will talk about some of the other areas that virtual reality has made some substantial differences.
Photographs and computer screens display information only in 2D, limiting views to flat images. Holograms, however, allow for the storage and reproduction of all information in 3D, and the technology relies on the ability to accurately manipulate light in three dimensions, the researchers said.
Within the various applications of optics investigated, it is clear that while technology has progressed and advanced over time, optical devices such as mirrors, prisms and lenses will still be very much in use in the future. The fundamental properties of these instruments are utilised and manipulated in a range of optical gadgets such as telescopes and projectors. Even in areas outside of visual aid and entertainment, optical apparatuses can be used to trick the eye and even showcase 3D images, as seen in holograms. Although metamaterials used in stealth technology lack obvious uses of mirrors, prisms and lenses, knowledge of principles observed in these tools such as reflection and refraction is used in the developing stages. In can then be said that the technology is based on understanding of the three aforementioned devices.
The story of augmented reality goes back as far as the early 1900’s when L. Frank Baum wrote the “novel The Master Key. Printed in 1901, the book mentions a “character marker” set of electronic spectacles that when you view someone through them would show a letter on that person’s forehead regarding their character.” However, the first invention to use some type of augmented reality would not come along till 1968 and Ivan E. Sutherland and his head mounted three dimensional display. “The fundamental idea behind the three-dimensional display is to present the user with a perspective image which changes as he moves.” This would allow for an illusion of 3D on a 2D plane. This however, wasn’t true augmented reality; yes this augmented what you see on a screen and gave an illusion of 3 dimensions, but it does not overlay actual reality with com...
Camera History.The first camera like devices can be seen as far back as Ancient Greece and China. This piece of early technology was called the Obscura, the invention of this was an important part in developing cameras and photography. A camera Obscura is a dark closed space that is shaped like a box with a hole on the other side of it. The light that comes through the tiny hole projects an image that meets the wall of the box. The image was then drawn by an artist; however, the image was projected upside down.
This research looks into the potential of augmented reality and more specifically spatial augmented reality. The purpose of this paper is to give the reader an understanding of what as well as where augmented reality has come from and how it is being used today. The paper will examine into different examples of augmented reality and how the term is not specific to a certain technology.
In India, optical illusions are being used to help save lives. Images of speed bumps are being painted onto the road, to slow drivers down. They are painted as optical illusions, as they look three-dimensional, but in reality, are just paintings. In a parking garage, there is an image of a girl with a ball, designed to look 3D. It causes drivers to drive with caution, although it is only an optical illusion. Optical illusions are being used often to help with safety enforcement.
The first optical illusions was created/discovered in the fifth century B.C. A Greek philosopher, Epicharmus, was the first to answer the questions of at the time the incomprehensible illusions. His explanations for these mysterious illusions had to deal with
A microscope is an optical instrument that allows you to see objects which are not visible to the naked human eye. The most common type of microscope is called the optical microscope, which uses lens to for images from visible light. Another type of microscope is called electron microscope and the way they work is that, they form images from beams of electrons.