1. A medical apparatus comprising: a first imaging device comprising a first image sensor having a first field of view; a second imaging device comprising a second image sensor having a second field of view smaller than the first field of view; and a processor configured to: process a first image acquired by the first image sensor so as to generate a first processed image having a first image magnification, process a second image acquired by the second image sensor so as to generate a second processed image having a second image magnification, adjust the first image magnification by digital zoom of the first processed image to be equal to the second image magnification so as to form an adjusted first image, and generate a stereoscopic image based on the adjusted first image and the processed second image.