Making a hologram requires illuminating holographic film or plates while they are positioned in front of or in close proximity to the desired holographic object. The process generally involves a list of supplies that includes the holographic film, chemical developers, and set-up equipment. The set-up varies depending on whether individuals create reflection or transmission type three-dimensional (3D) images. Making holograms generally requires an area free from light and motion. Supplies and tools can be purchased separately, but affordable all-inclusive kits are available that produce the popular 3D images relatively easily .
Reflective holograms are made by aiming a laser light toward holographic film, with the object behind the film. The transmission method to make a hologram involves using double concave lenses and mirrors that split the laser beam in two. The object beam travels through the lenses to the mirrors, toward the object and onto the film. The reflection part of the beam travels in the opposite direction and is deflected toward the film. The path traveled by the light beams resembles an enclosed upper case W.
Either method used to make a hologram illuminates the object and exposes the film at the same time. Following exposure, the film usually is bathed in bleach and exposed to developing chemicals. Each type of holographic film requires chemicals made for specific film or plate types. The chemicals are activated when mixed with water. Some types of holographic film develop automatically, without the need for additional processing.
The light source required to make a hologram is usually a diode laser. Lasers provide a uniform beam of single-wavelength light. Depending on the hologram process used, the light beam may be bent and spread using double concave lenses and mirrors. The laser must have a power supply, allowing it to illuminate continuously for an extended period of time. The laser used to make a hologram must warm-up for a minimum of 10 seconds to ensure a constant, steady beam.
Holographers may place a sheet of cardboard or similar opaque substance between the laser beam and the holographic film. Once the laser warms, they remove the obstructing device for a few seconds, which exposes the film. After adequate exposure, the shuttering device is replaced in its former position. To ensure a clearly developed image, the laser, film and object must be stabilized along with any lenses and mirrors. Even the slightest vibration can create a blurred image.
Ensuring the vibration free environment, required to make a hologram, can be accomplished easily by using sand or sugar filled styrofoam cups. Artists generally attach clips or clamps to the laser, film, object, and any lenses or mirrors and then position these devices directly in the granulated substance. More elaborate set-ups involve motion-absorbing tables, layered with concrete, wood, inflated devices, and an eventual top layer of sand.
