| 摘要 |
The lens 12 is shifted to a focus setting corresponding to a distance greater than that determined by the automatic focusing system, in order to make full use of the available depth of field. The depth of field available varies inversely with the increasing size of the aperture. In the preferred form of the invention an acoustic rangefinder is used, the aperture is set by a light metering system, and the same light metering system is used to preload a focus control counter (88, Figure 6 not shown) with 1, 2 or 3 pulses depending on subject brightness. <IMAGE> |
