METHOD OF CALCULATING ACTUAL EXPOSURE TIME AND IMAGING APPARATUS APPLYING THE SAME, OPTICAL EQUIPMENT, CAMERA SYSTEM, AND DEVICE FOR MEASURING ACTUAL EXPOSURE TIME

摘要

PPROBLEM TO BE SOLVED: To obtain accurate amount of luminous exposure even if a mechanical shutter has only a simple control mechanism and performs accelerated motion. PSOLUTION: The acceleration of the shutter is calculated from the elapsed time between two points during shutter close operation, and the relationship between the displacement of the shutter and time is obtained from the acceleration. By using the relationship between the displacement of the shutter and time, the relationship is obtained between the area of an opening formed by the diaphragm of a prescribed F value and the shutter, and time. The opening area is integrated in terms of time, and a total amount of luminous exposure in a period is obtained until the shutter and diaphragm close the opening diameter of the prescribed F value completely. The total amount of luminous exposure is divided by the amount of luminous exposure per unit time calculated from area when the opening of the prescribed F value is opened. PCOPYRIGHT: (C)2007,JPO&INPIT