An image seen by eye or by camera is aways the apparent origin of the light rays, not the light rays themselves. You may know this from ray diagrams with a virtual image, in geometrical optics. When looking at a rainbow by eye or by camera, the rainbow image is the apparent origin of the light rays. It is a 42° circle at *infinite* distance. The cone which is the path of the light rays is *not* the rainbow image (although that is a common misconception). In summary, the rainbow image is at infinity, whereas the cone and the light rays are nearby.