In its most general sense, a hologram is any information stored as a pattern of wave interference. In most cases, the information represents a three dimensional image and the pattern is recorded on film. After exposure and development, the film acts like a lens with a memory, focusing light into a 3-D image in the space around it. The pattern recorded on the film is not a focused picture, as in photography. Rather, it is a microscopic pattern of laser light wave interference, which focuses the light passing through it, by the process of diffraction.
The holographic image is very colorful, high in resolution and often animated. The effect on the viewer is like magic. You walk by a transparent sheet of film, and see a spectral image hovering, turning, and moving in the air in front of you.
This recorded interference pattern then acts as a diffraction pattern, which can bend light passing through it. Basically, when the hologram is illuminated with light resembling the original reference beam, the light is diffracted into a replica of the original object beam. When you look into that beam, you see a perfect image of the subject, located exactly where it was during exposure. The finished hologram film is usually laminated to acrylic or glass for convenience.
Most display holograms today are made in a two step process. A master hologram is first made of the subject, and it is viewable only with laser light. The image from the master is then used as the subject of a second hologram, the transfer, which is made to be viewable with ordinary light, suitable for display. With this process, the image in the transfer can pass right through the film plane, several masters can be combined onto the same transfer and image colors can be controlled by the placement of the masters. Extra transfer copies can also be made directly from the original masters.
Holographic stereograms involve a three step process. First a short strip of movie footage is made of the subject, as it rotates. This is then converted into a holographic master in a stereogram printer, and the transfer is then made in the usual way.
You look directly at the hologram film to see the image. The film may be as large as 1.1x1.8 meters,
weighing only a few pounds, and should be held at a convenient height. The image appears when a small
lamp (ordinary 50 watt mr-16 halogen, LED, projector beam, flahslight etc.) is aimed at the hologram from the correct angle. Reflection type
holograms are lit from the front, and transmission holograms from the rear. Lighting can be from above
or below, but once the hologram is made, the lighting angle is fixed. HNI packs a detailed lighting diagram
with every hologram.
Todays holograms are extremely bright, easily visible in any indoor situations. People like to move around and see the image twist and change, so very small spaces are not recommended.
Most people have seen small holograms, and have been amazed. Now picture that same magic in the size of a door! These images get attention. They are powerful tools wherever an audience needs to be reached:
Technically, this is a myth, originating from 2-dimensional science fiction movies.
The idea is to "project" a 3-D image into empty space, viewable from anywhere. Some movies
even suggest limitless animation sequences in full color, projected from tiny lenses. Full color can be achieved
in holograms, but animations are limited to about 10 seconds. And light doesn't turn
corners in empty space, unless you're near a black hole. So viewing from all directions is problematic
Recently, however, the cylindrical hologram has been improved and expanded to large format with a 2-step process developed here at HNI. These images can be seen from all sides in a continuous 360 degree circle, animating as well as rotating as the viewer moves around them. The resulting effect is remarkably similar to Leia and other Hollywood holograms. We are now able to produce 26"(66cm) high by 27"(69cm) diameter, animated cylindricals in multiple colors, with greatly improved image quality. Even better, there is no "projector", computer or laser, and no moving parts - just the clear film cylinder and a small light bulb.
Recent stereogram printer technology has vastly expanded the realm of holographic imagery. HNI can now work in large format with practically any subjects, including:
Images can be reduced or enlarged 50x or more, and original recordings can be accomplished on-site in ordinary light. Three dimensional images, however, require three dimensional subjects. A single photograph will produce only a flat holographic image.
You tell us what you need, and we advise you on feasibility, cost, lighting and installation. The details of the project are then written up in our standard order agreement form for your approval, before work begins. Subject matter may originate from the client, or in many cases, we create it. Then we produce the hologram. Installation is simple, and instructions are included with each shipment, or arrangements can be made for on site installation by our staff.
For more information, or to order a sample display kit, contact us at 802-658-2275 or by fax at 802-658-5471. Also, view our
stock image list or the anatomy of a hologram.