Propeller Aliasing

Many folks, who have tried taking a picture of a spinning airplane propeller with their cellphone cameras, have been surprised by the results. The pictures show images of ghostly propeller blades, floating in the air, totally detached from the airplane. Here is how this happens:

When a slow scanning digital camera (like the ones on many cellphone) captures an image, it does not expose all the pixels at the same time. Rather, it exposes and captures one row of the sensor at a time and then moves on to the next row. This simulated video demonstrates, in slow motion, how this results in images of floating detached propeller blades.

Category:

Education

Tags:

• propeller
• image aliasing
• iphone camera
• cellphone camera

[driftability]

Props on that, good explination.

[GoGoGadgets]

"A little bit of light jazz" by DJ Jazzy Jeff

[balthcat]

@driftability It even has PLAN(e) in it :(

[Northern206]

Can you send me the song?

[Northern206]

@GoGoGadgets This isn't a real song, can't find it anywhere. You know where to find it?

[jordinyc]

YOu should have looped it a few times.

[kclewell]

AT&T?

[rattielover87]

Nice.

[bokukokubo2008]

なるほど。。

[IKNOWITSADUMBCOMMENT]

aaaah! ok thats good! thank you for this video!

[resomer]

thx.

[katiekawaii]

@goatgoat It's really brilliant in its simplicity.