Curvature on a sphere, tested with 3dsmax @MathiasKp

Uploaded April 2016 | Updated September 2026, 1 week ago

3D model which shows the amount of curvature of the horizon which can be seen on a sphere with the radius of 6371 km/ 3959 miles. The view is rendered simulating a 50mm lens which is a good approximation for the human vision, photo.stackexchange.com/questions/34640/what-lens-focal-length-most-closely-resembles-the-perspective-of-the-human-eye.

A year after I made this video I found a lens that is very close to recilinear (no distortion) which makes it perfect for finding the left/right curve of the horizon https://flic.kr/p/WcGDHb

Link to screenshot at different heights:
3,280ft/1km https://flic.kr/p/GotvCx
75,440ft/23km https://flic.kr/p/G5bphY
100,000ft/30,48km https://flic.kr/p/FyPVVw
152,400ft/50km https://flic.kr/p/G5bpfd
304,800ft/100km https://flic.kr/p/FyPVSf
609,600ft/200km https://flic.kr/p/GnEgF9
1,524,000ft/500km https://flic.kr/p/FAxLn2

Curvature on a sphere, tested with 3dsmax

Ferry from Bornholmslinjen behind horizon, 30x stabilized, March 11th 2019

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$Why is the bottom part of Turning Torso behind water? Two hour timelapse of the view to Turning Torso over 21km, starts at 1:14 . No sign of varying refraction or mirages. Still the bottom part 22m is obscured by water, while observing from 0.8m. Air and water temperature, 2-3°C More weather data can be seen here, https://flic.kr/p/24MHUuK Camera position: http://www.google.com/maps/place/55.65236,12.64811 Height of Turning Torso, https://flic.kr/p/UHaPbQ Daylight photo, https://flic.kr/p/24LsFgM Night photo, 5sec, https://flic.kr/p/24LsEXv Night photo, 10sec, https://flic.kr/p/GtqNua #TurningTorsoFlatEarth$ $A ferry from Bornholmslinjen hiding behind the horizon, March 11th 2019 In this video I show how ships disappear bottom up behind the horizon. I didnt have a tripod with me so the footage is very unstable. Dandypanty made a stabilized version: https://www.youtube.com/watch?v=oVMxohidO40 The ferry is sailing between Rønne (Denmark) and Ystad (Sweden), https://www.marinetraffic.com/en/ais/home/centerx:14.4/centery:55.2/zoom:9 Ferry: https://www.marinetraffic.com/en/ais/details/ships/shipid:155510/mmsi:219017081/vessel:EXPRESS%201 On a different day (19th of March) I used an app to get the position of the ferry. I made a collage with all the needed data to calculate amount obstructed here https://flic.kr/p/2dVCxfR Ferry height estimated based on photographs: 24m Observer height: 4.05m Distance: 21.6km Amount hidden geometrical on globe Earth: 16.3m Amount hidden including std. refraction on globe Earth: 12.9m Amount hidden observed: ~13.3m$