On determination of crystal orientation by light figure method, many reports have been made by several investigators.
This method is a convenient and rapid procedure, a technique so suitable to a practical orientation determination of crystals.
It is known that the symmetrical characteristic of light figures corresponding to the symmetries of planes are invariant, while the surface treatment is different. But, the exact mechanism of pattern-shaping of light figure is not known. The present work was initiated to make a more detailed study of the relation between light figures and surface structures.