Holography is a technique of
(1) recording a permanent, sharp two-dimensional black and white or multicolour photograph
(2) recording a permanent three-dimensional multicolour photograph
(3) recording a permanent three-dimensional black and white photograph
(4) recording a permanent three-dimensional photograph of a given single colour or a multicolour
Answer: (4) Holography is a technique that enables three-dimensional images to be made. It involves the use of a laser, interference, diffraction, light intensity recording and suitable illumination of the recording. The image changes as the position and orientation of the viewing system change in exactly the same way as if the object were still present, thus making the image appear three-dimensional. The holographic recording itself is not an image; it consists of an apparently random structure of varying intensity, density or profile. Holography is a technique that enables a light field, which is generally the product of a light source scattered off objects, to be recorded and later reconstructed when the original light field is no longer present, due to the absence of the original objects.
