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FE: Lens Correction applied on a Video from Space

This is my version of the Video Flat Earth? Proof? 35mm Camera Perspective Space Experiment 2017. The Original Video is Flight 3: GH2 Vent Cam from Blue Origin.

I applied a lens correction filter in Adobe Premiere Elements of -28, the setting for a typical GoPro camera fisheye lens, and cropped the video from the bottom to get rid of the very wide angle distortions. So the original Field of View of about 90° is reduced to about 65°. This is the natural Field of View for humans. It corresponds to a focal length of 33,9 mm. Note: cropping the video does not introduce any distortions. Lens wide angle lens corrections shrink an image in radial direction to undo the barrel distortions. They do not manipulate the image in any other way.

The following video shows the real shape of the earth from ground until 240 000 ft altitude and back in one single uncut shot. The lens correction is applied without changing it throughout the whole video. I did not try all lens correction settings until it matched my expectation. The corrected video shows no change in any shape of the earth as it moves around in the frame, which is demanded from an undistorted video.

As you can see, the lens correction acts symmetrically about the center of the image. It streches the edges away from the center which results in straightening bent straight lines. In this way the barrel distorion of fish-eye lenses is corrected without changing the Field of View. The big Field of View causes sometimes weird perspective distortions that look "not right" for humans. To get rid of them one can crop the image to a smaller more natural Field of View, as I did in this Video.

Lern more about Lens Distortion and the Curvature of the Earth.

Ground Scene analysis of Jasons Video

It is easy to recognize that Jasons video is deliberately manipulated to show a flat horizon he expects we should see. But if the earth were flat, we would either see the ice ring, or if we only can see so far, we would see a circular view limit around the observer, which from this altitude would not appear as a flat horizon. We certainly can not see thousands of miles far in the footage, so even on the flat earth there should be a circular view horizon. Another sign of false correction is the u-shaped desert in the background. Google Earth shows that this area is flat. The shape of the shadow of the rocket is way too much streched out horizontally. It is very distorted.

I took the pictures of this analysis from Jasons video: Flat Earth? Proof? 35mm Camera Perspective Space Experiment 2017.

Tipp: Click onto the picture to swap between two images for fast comparison.

  • Jason Kirby's:
  • Original Fish-Eye
  • Transformed
  • Orig+Displacements
  • Trans+Displacements

With the Displacements-Tabs you can see how the Viedo was distorted by Jason. He "removed" the fish-eye distortion locally on the horizon by introducing other distortions. A lens correction filter would remove the fish-eye distortion gradually and symmetrically over the whole image evenly.

Lern more about How Lens Distortion works.

The displacement lines connect two identical points on the original and the transformed image. As the displacement lines show, he pulled down the middle field, pulled up the right edge a little bit and streched the whole image horizontally. This transformations applied to the image in space bend down the earths horizon in the middle of the image, bend up the horizon at the right edge and strech the whole horizon. That is exactly the transformation needed to get the bent horizon of the video straight.

But things in the foreground are distorted, more than from the fish-eye lens itself: the visible part of the rocket is distorted, check the small triangle with the hole, and the shadow of the rocket on the ground. On the landscape the distortions are not abvious, because wie cannot know the right shape of the landscape without direct comparison. But here you can compair it with the original and see the streching applied to the mountains.

Ground Scene analysis of Walters Video

  • Walter Bislins's:
  • Original Fish-Eye
  • Lens Correction

I applied a lens correction filter to the whole video which symmetrically and evenly corrected the barrel distortions introduced by the fish-eye lense. Because such corrections on very wide angle images can cause weird perspective distortions that looks "not right" because we naturally hav not such ab big field of view. I cropped the video a bit to get a smaller natural field of view of about 65;°.

The horizon is now straight. The rim of the rocket on top is now round as it is in realty, but was straightened by the fish-eye lense. The shadow and the small features of the rocket are not distorted.

Space Scene analysis of Jasons Video

  • Jason Kirby's:
  • Original Fish-Eye
  • Transformed
  • Orig+Displacements
  • Trans+Displacements

The same transformation, pulling down the middle and slightly pushing up at the right edge straightens the earth's horizon as expected to a straight line. The horizontal stretching helps straightening the curve even more.

In my eyes the applied transformations in Jasons Video look not like a lens correction filter. May be I am wrong but then I would like to know what filter he used and he shure can tell me that. I will update this text to include this information.

Can we conclude the true shape of the earth seen from space from this video alone? I don't think so, because we need to know the used lense (what kind of fish-eye, focal length) and the applied transformations in the video unless we have other related measurments that support a any hypothesis.

Lens corrections are exactly defined mathematical transformations on the basis of optical laws. They are intendet to remove e.g. barrel distortions introduced by fish-eye lenses. To get the image, where we can tell the real shape of objects shown, we must apply the correct lens correction. Not the one that "looks right", but the one that exactly undoes the distortions introduces by the lens.

I want to emphasise that Jason did not claim that his video shows the real shape of the earth nor that his transformations are applied lens corrections. But Flat Earther misuse his videos to prove, that the earth is flat. To counter that I made this page.

Space Scene analysis of Walters Video

We can here clearly see the curvature of the earth on the following images. How do we know that this curvature is real?

I have programmed an app Finding the curvature of the Earth. This App can calculate, how a globe with the size of the earth would look like from any altitude under a specific field of view. In the Tab "Lens Correction with Grid", the calculated grid for this altitude and field of view is overlayed onto the image to see, wether the image matches the expectations of the globe model. See the result yourself.

My app is not made up to fool people or to fake curvature, but it is based on simple geometry and perspective laws. The source code can be examined, there is no hidden trick. You can check the calculated values like distance to the horizon, drop of horizon, angular size of the earth from big distancies ect. with measurments in reality and with calculations from other websites.

  • Walter Bislins's:
  • Original Fish-Eye
  • Lens Correction
  • Lens Correction with Grid

Conclusion

It is possible to get the real shape of the earth from video footage taken with fish-eye lenses by applying the correct lens correction filter. As the example on this page shows, it maches the calculations of a globe model exactly. You don't need to turn knobs until you get a picture that maches someones expectations. You just have to know the data of the used lens und feed that into a good video editor and he spills out the real shape of the landscape, in this case the spherical shape of the earth at high altitudes.

The following facts are strong evidence that the earth is sperical:

  • The lens correction filter shows a flat earth on ground and a smooth transition to a sperical shape as the rocket gains altitude.
  • The shape of the earth from space on the video, after applying the lens correction, maches the shape obtained by geometrical calculations for a sphere of radius 6371 km from an altitude of 240 000 ft.
  • The geometrical calculations of my App are proven to be correct by compairing the calculations with images where shown distances are known, and by crosschecking calculated values with calculations from other websites (See here).
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Created Sonntag, 16. April 2017
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Changed Freitag, 8. Januar 2021