LASER TRANSMISSION HOLOGRAM
How to make a hologram – Postcards produced for Hologram Museum/Gallery Tourist exhibition, Drottninggatan 100, Stockholm
How to make a Laser-Transmission Hologram Copyright Hologram Museum/Gallery Sweden
The tiny beam from a laser is “cleaned” and diverged when it passes through a spatialfilter.
The object is illuminated by laser light, objectlight, and some of this light is reflected against the hologram plate. The plate is also illuminated by light which is directed from the laser with a mirror, referencelight.
The hologram is built up by a pattern of fringes, an interference pattern. This pattern is created when the object and the reference light meets, interferes, in the holographic plate.
This type of hologram can not be seen in ordinary light from a spotlight only by using laserlight.
REFLECTION HOLOGRAM – Type Denisyuk
The object is illuminated by laser light directly through the hologram plate. The hologram is built up by a pattern of fringes, an interference pattern, which is created when laser light from the object and direct light from the laser, interferes, in the holographic plate.
This hologram can be seen by using ordinary spotlight.
THE DIFFERENCE BETWEEN PHOTOGRAPHY AND HOLOGRAPHY
The Photography register what the camera’s lens registers (A). How the object looks from any other points outside the camera lens is not registered (B). The hologram however, register the object from each point at the object (C, D)) without the help of a lens or a camera.
It’s as if thousands of eyes on the hologram surface each can see the object.