In Berlin-Wilmersdorf we have a skating stadium with a 400 meter skating ring and a ice hockey field inside. Standing inside the of ring I was wondering what may happen if I would trace somebody or something moving on the curve of the skating ring, using the camera of my mobile phone in panorama mode.

So I just tried. I was a bit surprised by the results.

As panorama pictures consist of multiple images stitched together, the object(s) in the focus area will appear several times in the final image. As objects will change their size with distance, an object moving in a circle around the photographer will not change the distance and the movement finally appears to be linear. A linear movement will appear as a curve.

Have a look on the images and try yourself.

Step 1: How to and Results: Curve to Linear

It's really simple to do and most recent mobile phones will come with a camera and a panorama function in the camera software.

Place yourself at or near the center point of the curve.
Select an object or person that is moving with a steady velocity, not too fast and not too slow.
Start recording when the person/object enters the curve and move the camera continuously and slowly, keeping the object at the same relative position.
Stop recording when the object is leaving the curve.
I finally just had to truncate the pictures just a bit, cutting away some ground and a bit of sky.

The panorama function of the camera is stitching the panorama image from several smaller images. So if you track an object moving on a curve, the object will appear on many of these pictures. If the object is moving around you, in the final image it will look like it is moving on a straight line. So you basically get something that looks like a simple stop-motion image.

If you are not in the central point of the curve, the object will appear larger when nearer and smaller when further away. You can see this effect on the first image on the introduction step.

On the pictures in this step, you can see the same process, the movement of the ice polishing vehicle, once as panorama image and as seen from the side.

Try it yourself. The first shots may not be perfect, so just try several times. Have fun.

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If your interested in the topic, you may like to have a look on my previous instructables on spectroscopy,

https://www.instructables.com/id/Microbit-Spectrom...

https://www.instructables.com/id/Filtered-Rainbows...

https://www.instructables.com/id/A-Mimimal-Six-Col...

https://www.instructables.com/id/An-Inexpensive-Ph...