How does holography differ from ordinary photography?
The main difference between holography and photography is that ordinary photography produces a two dimensional image, holography produces an image that is visible as a three dimensional image. In this context id must be noted that 3-dimensional picture seen using special spectacles consist of two images, such that each of our eyes is views a different image, resulting in the three dimensional vision. In contrast the holographic image requires no special spectacles for viewing. There is one common image formed and both the eyes view this common image.