I enjoyed the video up until about the 8:40 area and beyond, when I found it a bit harder to believe that view provided by a small weather balloon, even with a light payload. I suppose lens lengths would produce varying degrees of "curvature", even at 37 Km altitude (est). Best technology (and much larger balloons) back in the '60s took a much heavier payload only up to around 35 Km, so this challenges my very limited understanding of the science behind this, and what appears to be a balloon with most of it's volume filled prior to release. I'd love to know more about this.