Kip Daugirdas’s video “56 Miles (90 km) Above Earth – Successful Amateur Rocket Launch” shows the curve of the horizon. This is visible when the horizon is on either side of the center of the frame. The camera is a GoPro with a rectilinear lens.

The horizon’s curve is easily visible no matter where the horizon is in relation to the center of the frame. Here is a link queued up to the horizon above center of frame: https://youtu.be/4QsEPEhq5yk?t=501

Here is a link queued up to the horizon below the center of frame: https://youtu.be/4QsEPEhq5yk?t=494