Minimum focusing distance alone does not determine magnification.

The key point is that the quoted minimum focus distance is often measured from the sensor plane, not from the front of the lens. A macro lens can be physically much longer at close focus, so the working distance from the front element to the subject may be far smaller than the spec suggests.

In your example, the Laowa reaches 5x only at a much shorter front-of-lens working distance (about 40mm), not at the full 17cm distance you quoted. Also, the stated focal length is typically the focal length at infinity focus. When a lens focuses very close, the lens elements move and the effective optical behavior changes. Macro lenses are designed to extend much more at close focus, allowing much higher reproduction ratios.

So there is no contradiction: two lenses can have similar listed minimum focus distances yet very different magnification because:

• the distance is measured from the sensor, not the front element,
• lens extension at close focus differs,
• the effective focal length/optical configuration changes at close focus,
• one lens is specifically designed for high macro reproduction and the other is not.