WaBis
walter.bislins.ch
Bild: 2017-07-14_FE_Balloon_94000ft_42mm_no_fisheye_grid.png
| Upload | Freitag, 14. Juli 2017; wabis |
| Source | Youtube: TestingTheGlobe's Second High-Altitude Balloon Launch, Rob Skiba, Time 1:47:51 |
| Grösse | 626 kB |
| Masse | 1466 x 751 Pixel |
| Tip | Click image to zoom |
Description
Image from a high altitude balloon taken with a GoPro, fitted with a 7,2 mm = 41 mm 35 mm equivalent lense, no fish eye distortion. I put the altitude of 94 000 ft = 28,7 km, f = 41 mm, FoV = 55,6° and aspect ratio 16:9 into my Earth Curvature Simulator and overlayed the calculated grid over the footage.
To eliminate the possibility of a small distortion I choose an image where the horizon crosses the center of the screen. Lines crossing the center of a lense don't get distorted.
It matches perfectly, the image shows the predicted curvature of the earth.
Some data for this image from my simulator:
| Altitude | 94 000 ft = 28,7 km |
| Focal Length GoPro | 7,2 mm |
| 35 mm equivalent Focal Length | 41 mm |
| Field of View | 55,6° |
| Distance to Horizon along Surface | 603,6 km |
| Distance to Horizon Line of Sight | 605,4 km |
| Dipping Angle | 5,428° |
| Drop from Surface | 28,57 km |
| Drop from Eye Level | 57,27 km |
| Grid Line Spacing | 13,4 km |