1. An image sensing apparatus for sensing a subject whose three-dimensional image is to be generated, comprising: at least two image sensing means, each having an optical system for sensing the main subject; and adjustment means for adjusting an image sensing condition parameter for each optical system of said at least two image sensing means on the basis of images of the subject sensed by said at least two image sensing means so that images of said subject project within image sensing areas of said at least two image sensing means, and that the images fall within the focus depths of the optical systems of said at least two image sensing means.