About Holographic Images

Background

For centuries people have been fascinated by the idea of ethereal, other worldly, floating images. Many cultures associated the concept with religious beliefs or ghosts and spirits from the afterlife.

Victorians celebrated the concept with special tricks and illusions and coined a phrase for this phenomena - Phantasmagoria!!!

Sometime during the late-1970’s people started to think of this concept as a hologram.

The Star Wars films were possibly instrumental in shifting peoples thinking in this direction. It is now hard to see a film based in the near future without there being floating mid-air imagery presented as the way we will all be viewing displays in the not so distant future.

The iconic image of R2D2 projecting a blue fuzzy “hologram” of Princess Leia into the space in front of him has become the popular received definition of a hologram…but it is not really a correct definition.

Holographic Illusions are not "True Holograms"......but most people think they are better!

Interestingly, there is a proper definition of a Hologram; which really has little to do with a moving aerial projected image. These laser-etched diffraction gratings are not movies; they are still images which capture the 3 dimensions of the world around us but in such a way as to create a virtual volume on a 2D plane. This volume can be explored simply by moving the viewers position in respect to the image.

In other words, you view these “true holograms” from one side and you can see one aspect of the virtual volume. If you then move to the opposite side, you will see things that were obscured from the previous positions view… So the 3D appears because the viewer moves around in front of the static picture.

This video is of a true; full colour hologram. The image of R2D2 is a still image but conveys to the audience a different angle of view when looking at it from the left hand side compared to looking at it from the right hand side. These are not audio visual displays merely clever still images.

It would technically be possible to make a movie out of such images if you were able to present 25 slightly different frames of these true holograms every second to the viewer. So far this has proved too costly to do and in the modern world of digital distribution of video content, returning to slide projector technology does not seem attractive. And furthermore; the concept of delivering content to the viewer by physical methods rather than a digital platform seems like a step backwards.

What people really want is aerial floating imagery that can be observed in the real world not just as a computer generated augmentation within a movie.

Why "Holographic Illusions" are better than "True Holograms"

We think you will agree that whilst true Holograms i.e. the laser etched diffusion gratings are good, the holographic illusions we produce, are better. The reasons for this are: -

1. Holographic illusions are highly realistic full motion moving images i.e. 25-120 frames per second can be rendered and presented to the viewer. Giving highly realistic full colour motion images.

2. The content is easier to produce than for a real or True Hologram.

3. They can be made to look like they occupy real space / volume rather than have the volume encoded into the picture this means people can interact with virtual objects more easily

Professor Sir Colin Blakemoore of Oxford University and BBC interacts with Hologram of brain during a workshop on consciousness


4. Holographic illusions can be very large size of an aeroplane or a house.

5. Holographic Illusions can reproduce a human or an animal images and make them look like they are really there when they are in fact just an illusion.

6. We can fake the aerial projection so well you will think you are really experiencing that Obi Wan Kenobi and Luke Skywalker moment when Princess Leia emerged from R2D2 in holographic form.


The best definition of a true hologram is from Fundamentals of Optics by Jenkins and White p658 4th edition: -
The term holography comes from the Greek meaning whole writing. It is a two-step process by which (1) an object illuminated by coherent light is made to produce interference fringes in a photosensitive medium such as a photographic emulsion. (2) re-illumination of the developed interference pattern by light of the same wavelength produces a three-dimensional image of the original object. The viewed images viewed by this process have the appearance of the original object, including the differences in perspective one obtains with a change of the viewer's observing position - a full three-dimensional image.