Analysis of information sources in references of the Wikipedia article "Macro photography" in English language version.
When the entire lens group moves, the distance between the subject and the focal plane (shooting distance) is least at a reproduction ratio of 1:1. This makes for an interesting characteristic in that the distance between the subject and the focal plane must be increased in order to achieve reproduction ratios greater than 1:1. On the other hand, autofocusing demands that the shooting distance be gradually decreased with the transition from infinity to close-up. This is easier to grasp if you think of yourself with a camera in your hands. You mount the camera on a tripod with the distance between the subject and camera (shooting distance) fixed. When you press the shutter-release button halfway, the camera begins to focus (autofocusing). When you want to make the subject larger (take up a larger portion of the frame), you naturally move closer to it. When a floating mechanism is used, lens focal length and specifications change with shooting distance. While controlling these changes, focus must be designed so that the shooting distance always decreases until a 1:1 (life size) reproduction ratio is achieved.
