After revolutionizing visual art and record-keeping, photography remains valuable, even though a photograph is an incomplete documentation of light’s interplay. Because the human brain is capable of inference and intuitive connections, a photograph makes sense, but the disclosure of dimensions is limited.

This is where holography comes in. The prefix “holo-” means “whole” and “-graphy” indicates “picture-making.” So, photography- the making of pictures using light- isn’t making the whole picture, because it isn’t using the whole light, only as much reflection and diffusion as can be imprinted on a flat surface. All the colors are captured, but not the shape of the light.

Holography started out with discoveries in the development of electron microscopes- microscopes that create pictures by bombarding objects with electrons, the tiny particles that partly comprise atoms- which meant that images could be created of objects much smaller than could be observed by light. What’s remarkable about electron microscope images is not only the quality, but the concept that they are being created without light, that it’s all based on the electrons being bounced off the surface of the object.

Keeping this in mind, a satisfying conceptual leap can be made: just as electrons are bounced back, so is light. And unlike electrons, light can be seen. With a beam of single-colored light moving in one forward direction- otherwise known as a laser beam- it can be split and reflected from a mirror and from another object onto a chemically treated plate, which creates a recording of the light bounced off the object.

This recording works because the two sources of light create an interference pattern, where the waves of light are added together. So when the recording is exposed to regular light, it gets reflected where it was reflected on the object, and it is dark where there was no reflection or diffraction. This is what creates the image, a dynamic process of external light that becomes manipulated by the imprinted plate, rather than the fixed stasis of a photograph.

The great thing is that this is only one method of producing a hologram. There are two general categories of production: reflection and transmission. The method described above is an example of reflection, with a physical holographic recording as the end result, while transmission involves using a continuous source of light to create a virtual image that is present for as long as the laser is on, creating holograms of more depth.

There are a lot of things to keep in mind when making holograms, such as the stability of all the components during exposure, but it can be a very rewarding and appealing use of your personal laser.