Junior high school physics problems

First, the camera images, and the object distance exceeds twice the focal length; In addition, eating them all is equivalent to reducing the image;

According to the principle of convex lens imaging, when the object distance is more than twice the focal length, the larger the image distance, the smaller the focal length and the smaller the imaging.

Therefore, moving the camera backward is to increase the object distance; The inward contraction of the lens not only increases the object distance but also decreases the image distance, so the natural image will become smaller.

So choose C.