> If you extrapolate, the earth would be much smaller in these photos. At that height, the horizon would appear nearly as a perfect straight line. With a pinh

> If you extrapolate, the earth would be much smaller in these photos. At that height, the horizon would appear nearly as a perfect straight line. With a pinhole camera, it would be projected as a straight line in the image plane. Thus, the curvature here has to do with the wide-angle geometry of the lens. If the camera was pointing higher, you would see the horizon curved in the other direction (which would look even cooler!).