They take a fisheye. They adjust the curvature and focus point to ensure that the horizon is controlled by the centre point and curve. Possibly using shift and tilt techniques
They then rotate the image 180° to flip it vertically because we have trouble gauging things when flipped upside down.
Technically the earth should always be at the bottom of the screen and the Horizon near the middle, so by changing that perspective you can fool people's minds.
They take a fisheye. They adjust the curvature and focus point to ensure that the horizon is controlled by the centre point and curve. Possibly using shift and tilt techniques
They then rotate the image 180° to flip it vertically because we have trouble gauging things when flipped upside down.
Technically the earth should always be at the bottom of the screen and the Horizon near the middle, so by changing that perspective you can fool people's minds.