An image taking system includes a lens apparatus 1 and a camera 2 which performs a shooting using the lens apparatus. The system comprises a distance calculator 114 which calculates an object distance in each of a plurality of ranging areas 1 to 16 provided in an image-taking range, a distance information generator 114 which generates distance information indicating at least one of the object distance calculated by the distance calculator and a difference between the object distances, an extractor 115 which extracts, out of the plurality of ranging areas, a ranging area where the object distance calculated by the distance calculator is in a first range A, and an output image generator 203 which generates an output image including a shot image generated by the camera and the distance information corresponding to the ranging area extracted by the extractor.