Its been about two weeks since I watched this video about rolling shutter and also this video by Matt Parker whom I mentioned last time. Matt was showing the effect on fidget spinner, the new gadget that you simply spin and there is nothing really special about it (except that it spins).
Rolling shutter is the effect made by any “picture taking device” (as far as I know). So, for example camera or scanner (in my case). When cameras take pictures, they do so by scanning from top to bottom and saving up line by line of pixels. Similarly, how scanners do it except much faster so that you do not notice it. Scanner on the other hand is slow enough that when something is moving the pictures won’t make any sense. If I would move an object with the scanner, at the same speed it would smooshed across the whole picture because it does not see everything at once, only a thin line.
Really interesting stuff starts to happen when you spin something so that it goes back and forth (around and around). I did exactly that and it produced for example image above or the ones to the side.
It is interesting how the twisted shapes change with the speed that the fidget is rotating. The fifth and sixth picture are part of the same thing, fidget spinner spinning and being moved by me at the same time. The first one on the collage is spinning really fast, the second one not so much the third one is changing directions and the fourth one is really slow which makes for quite “solid” fidget spinner.
I recommend to try this at home, great and easy “experiment” (of course unless you do not have fidget spinner, then I do not recommend buying (life at stake)).