To make a hologram, the object is lit by light form a laser. This light reflects from the object and strikes a photographic plate placed nearby. At the same time, the laser beam is split so that it also reflects from mirrors and strikes the plate directly. The plate is then developed. A black and white pattern appears on it, producing a holographic plate. When one side of this plate is lit up by a laser beam and it is viewed from the other side, an image of the object appears behind the plate. The image is in three dimensions just like the real object but in the color of the laser light. Projection holograms can be projected by lasers to appear in front of the holographic plate. There are also special holograms that can be seen by day light because they can record an object from many angles with a great accuracy. Scientists use them to study the growth of crystals or the build up of dirt on old oil paintings. In the field of industries, holography is being used to prevent the pirating of the goods of big companies. In India also some big companies are using the holograms to distinguish their original goods form the copied ones.