| 摘要 |
An exposure control method for an image pickup apparatus 1 includes determining whether a zoom lens in lens group 5 has been moved and whether a focal length value F has changed. The value F is obtained from focal position information of a focus lens linked to the zoom lens. For a given change, an estimate is made for the change in focal plane luminance upon the image sensor 6 after a change in the value F. On the basis of the estimated focal plane luminance change due to the zoom lens operation, the camera shutter speed is adjusted by control unit 7 to ensure that the focal plane luminance is maintained at the pre-zoom operation level. Furthermore, a camera frame rate is also updated in accordance with the adjusted shutter speed. The method allows the preservation of the appropriate exposure level during zoom lens operations. |
