Photos of the Curve

To get a photo of the curve of the horizon it helps if you are at a good altitude. Commercial AIrplanes are not the best option. But from the cockpit, you can see the curve better since you have a wider field of view. Also, the windshield is required not to add distortion.

VIew from the cockpit of an airplane:

Another from a cockpit:

The Concorde flew higher than other planes, here is a photo of the Concorde at cruising altitude with the horizon in view:

Passengers on the Concorde personally saw the curve of the horizon. DC Rainmaker took this photo:

Feel free to analyze this photo. Contrast or Gamma adjustments make the horizon edge more crisp and horizontal compression shows the curve very nicely.

Here is one from photographer Santiago Borja Photography in the cockpit of a plane: