

The rolling shutter on a digital camera can give interesting effects - RiderOfGiraffes
http://www.globalnerdy.com/2009/01/13/cheap-camera-interesting-shot/

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defdac
I found this MatLab visualization of what happens inside the camera very
helpful in understanding how it works:
[http://scalarmotion.wordpress.com/2009/03/15/propeller-
image...](http://scalarmotion.wordpress.com/2009/03/15/propeller-image-
aliasing/)

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teilo
The article mentions that this is true of cheaper digital cameras, but in fact
SLRs have a similar effect. At high shutter speeds, the back curtain closes
shortly after the front curtain opens, causing the exposure to happen as a
slit of light that passes across the sensor or film.

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rimantas
Actually I am not sure you can get this effect on cheap camera. Which cheap
camera uses curtain shutter? And I would be _extremely_ surprised to see that
kind of shutter on the cameraphone.

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zefhous
That was taken on an iPhone. It happens in camera phones not because of a
physical shutter, but because the entire frame isn't captured at once.

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Terretta
Two examples of deliberately abusing this effect on a static subject (house
and church) by pivoting the iphone while taking the shot:

[http://farm4.static.flickr.com/3158/2421813332_3c36b3b808.jp...](http://farm4.static.flickr.com/3158/2421813332_3c36b3b808.jpg)

[http://farm4.static.flickr.com/3187/2421813434_dbdc309901_b....](http://farm4.static.flickr.com/3187/2421813434_dbdc309901_b.jpg)

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thamer
Here is a video of a plane propeller filmed with an iPhone 3GS, showing pretty
cool effects due to the rolling shutter: <http://vimeo.com/5934808>

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apu
There's some exciting work being done in our lab with a "coded" rolling
shutter, where you change the readout times on individual rows to give you
better pictures or videos -- high dynamic range, super-fast capture, etc.

There's no project page up yet, but this video explains most of the key parts:

<http://www.cs.columbia.edu/~jwgu/crsp_video.mp4>

If you want full details, here's the paper:

<http://www.cs.columbia.edu/~jwgu/crsp_final.pdf>

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gojomo
Could this be used to send 'secret' messages only visible to camera-shots of
certain specs/orientation?

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maggit
Yes. This could be an example of steganography, the art of concealing that you
are sending a message: <http://en.wikipedia.org/wiki/Steganography>

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wlievens
On the other extreme, there are cameras that take 70 thousand frames per
second. Yikes.

