When a photographer takes photos from a helicopter high in the sky to the ground, if the focal length of the camera lens used is 100mm, the distance between the film and the lens should be (

So when the object distance becomes larger, the image distance becomes smaller, and the image distance must be between 1 times the focal length and 2 times the focal length. At this time, the focal length is 100mm,

So The distance between the film and the lens is between 1x focal length and 2x focal length. The farther the object distance is, the closer the image is and the closer it is to the focus, so the distance between the film and the lens should be slightly greater than 100mm.