Abstract: An autozoom apparatus for a camera having an operating member for designating a first point and a second point in a scene to be photographed; a circuit using an angular velocity sensor for detecting a displacement angle of the camera when the camera is rotated from the first to second points; an autofocus circuit for measuring the object distance; a zoom encoder; a zoom motor; and a circuit for controlling the zoom motor. The autozoom apparatus calculates a focal length corresponding to the picture frame defined by the first and second points and makes automatic zooming to the calculated focal length.

Abstract: A photometer of a camera employs a MOS-type CPU having an open drain type transistor whose drain serving as an output terminal, a CMOS input terminal, and an input gate inverting an input with a value exceeding a predetermined potential. In the photometer, the transistor is set in a high-impedance state, thereby releasing a charge accumulated in a parasitic capacitor of a photodiode for generating a photoelectric current corresponding to an incident light amount. Thus, a voltage at the CPU terminal gradually increases, and, when it exceeds a threshold of a Schmitt inverter, the output of the Schmitt inverter is inverted. The time period from when the transistor is set in the high-impedance state to when the output of the Schmitt inverter is inverted is proportional to the photoelectric current. By measuring the time period, the photoelectric current value or luminance is detected.