1. Field of the Invention
The present invention relates to a camera capable of detecting the amount of hand trembling of the photographer by means of a focus detecting device.
2. Related Background Art
There are already proposed various cameras capable of detecting the amount of hand trembling of the photographer by means of a focus detecting device, for example as disclosed in the Japanese Laid-Open Patents Sho 60-166911 and Sho 60-166910 of the present assignee.
Such conventional examples are constructed so as to first focus the lens to an object by an automatic focusing operation, and then to detect the hand trembling in a state where the focusing is fixed.
Such an automatic focusing camera is naturally designed to effect an automatic focusing operation in the first place, and is generally capable, for the automatic focusing operation, of selecting either a mode in which the focusing operation is no longer conducted once the focused state is reached (hereinafter called "one-shot mode") or a mode in which the focusing operation is repeated regardless of whether the focused state is reached or not (hereinafter called "servo mode").
Also, such auto focusing cameras are generally equipped with illuminating means for illuminating the object in auxiliary manner in a situation where the focus state cannot be detected in the automatic focusing operation (such means being hereinafter called "auxiliary light"), in order to effect the automatic focusing as far as possible.
Unless the hand trembling detection is conducted with a fixed focus state after the focusing operation is conducted, the image signal to be used as data for detecting the hand trembling cannot provide a value suitable for such detection, so that exact detection of hand trembling becomes impossible. Consequently, in a camera capable of selecting either the "servo" or the "one-shot" auto focusing mode, exact detection of hand trembling cannot be realized if the servo mode is selected.
Also in the case where the focus state cannot be detected, the focusing may be achieved by the emission of auxiliary light, but the detection of hand trembling cannot be realized by such a method. Such an auxiliary lighting unit is either integrated with the camera, or, even if constructed separately, is fixed to the camera in use. Consequently, the auxiliary light vibrates when the camera vibrates, so that the hand trembling cannot be detected by the emission of auxiliary light. Thus, the emission of the auxiliary light for focusing preceding the hand trembling detection will be meaningless and merely a waste of energy.