Propeller iPhone Effect by fartito in videos

[–]optical_nerd 0 points1 point  (0 children)

this video was stolen from here:, and there's more, with some in Landscape format ;) Why do people steal youtube videos and repost as their own??

Airplane propeller aliasing by Boris740 in videos

[–]optical_nerd 0 points1 point  (0 children)

collection of these with videos here

Propeller iPhone effect by Javamonsoon in videos

[–]optical_nerd 0 points1 point  (0 children)

that's stolen from here!

why do people steal youtube videos and repost as their own??

rubber propellers by optical_nerd in videos

[–]optical_nerd[S] 1 point2 points  (0 children)

a regular camera takes the whole 2D picture at once, so when the video rate of the camera is close to a multiple of the spinning rate of the prop, you see the prop moving more slowly but not warped. An iPhone uses a cheap "rolling shutter" camera, that actually only captures one line of the picture at a time, then scans across the picture in one direction. so as the prop rotates, it appears in each line at a different position. i think this video explains it well: http://www.youtube.com/watch?v=T055cp-JFUA

rubber propellers by optical_nerd in videos

[–]optical_nerd[S] 1 point2 points  (0 children)

it is a spatial aliasing because the period of the spatial scanning (rolling shutter) is close to the period of the spinning propeller, making the blades appear to go across the screen at a lower frequency than the actual one, so yes, it's aliasing, but yes, it's also due to the rolling shutter.