ABSTRACT
If you are going to make successful multicolor holograms you need to know how to obtain correct color registration. All diffraction systems are sensitive to wavelength. The angle of diffraction of a beam is, to a first approximation, directly proportional to its wavelength. This means that if you want to have red, green and blue images (or red and cyan in an achromatic hologram) that coincide in both position and magnification, you need to do some geometry and trigonometry. If you are a reluctant mathematician (as are the vast majority of people) you shouldn’t be discouraged, as there is nothing involved that you can’t solve by pushing a few buttons on a pocket calculator. For this small effort the rewards are immense.
