| 摘要 |
PURPOSE: To enable a stable voriable magnification operation by inhibiting a focal distance control means from executing the variable wognification operation in the case a distance between a rear focus and a focal position is smaller than a prescribed value. CONSTITUTION: A quantity (x0 ) of extending a focusing lens group of a photographic lens 3 from an infinity end is calculated, the present distance information (f0 ) of the zooming lens group is inputted, then, the image magnification m0 =x0 /f0 is obtained. In the case it is judged that the (x0 ) is smaller than the prescribed value, the image magnification is too small to execute a constant control of the image magnification, a practical effect is not obtained on the image, then, an image magnification constant control flag is set '0' and the variable magnification operation by the focal distance controller is inhibited. Thus, as for the camera provided with the image magnification controller 1 for executing such the operation, the practical effect is secured on the screen under the image magnification control, and also, the image magnification control is not executed under such a situation that the control operation is liable to become unstable, so that the power varying drive control is stably executed. |
