How Many Fingers Am I Holding Up?
September 5, 2010 6:29 PM   Subscribe

The Rolling Shutter Effect: a mobile phone camera is fairly quick, but when the objects you are recording move faster than the scan rate, cool things happen. Mucho previously at MeFi.
posted by bwg (33 comments total) 19 users marked this as a favorite
 
This is why I no longer get on airplanes... at my age, I'm not sure which reality is real.
posted by HuronBob at 6:31 PM on September 5, 2010 [2 favorites]


Oh, I thought that plane was dropping boomerangs.
posted by chillmost at 6:44 PM on September 5, 2010 [5 favorites]


There was another neat video of this effect on Vimeo.
posted by msbutah at 6:45 PM on September 5, 2010 [5 favorites]


Hah, I just ordered the Nikon D90 (upgrade from the D40) which is supposed to suffer from this. I think I'm going to try to turn the bug into a feature.
posted by dunkadunc at 6:57 PM on September 5, 2010


What's worse is that I'm having trouble wrapping around why this does what it does....once I know, I can play around with it. But it's killing me that I can't just look at it and say "well, it's because...."
posted by nevercalm at 7:15 PM on September 5, 2010


It's a lot scarier on a helicopter.


(Also, didn't you know that propeller planes stay in the air by firing boomerangs at the ground really quickly? It's physics.)
posted by schmod at 7:21 PM on September 5, 2010 [20 favorites]


I've gotten this effect a few times. The first two were on cortex's cat site at one point.
posted by cjorgensen at 7:22 PM on September 5, 2010


That helicopter one must not have a rolling shutter, since the blades aren't distorted. Is there some other kind of shutter?
posted by smackfu at 7:28 PM on September 5, 2010


I guess it's a lot cheaper than the old trick of Intentional Misuse of a Scanning Back
posted by scruss at 7:28 PM on September 5, 2010 [7 favorites]


The helicopter one must just be a specific choice of helicopter and camera such that the RPM of the rotor is evenly divisible by the framerate of the camera.
posted by kafziel at 7:31 PM on September 5, 2010


Hah, I just ordered the Nikon D90 (upgrade from the D40) which is supposed to suffer from this.

It does, although if you refrain from jerking the camera around or filming fast-moving objects you're fine.

Rolling shutter is one of the reasons people told me I was crazy a year ago or so when I said I wanted to make movies on a DSLR. Fast-forward to now and major network TV shows are being shot on Canon 5DmkII's.

posted by drjimmy11 at 7:33 PM on September 5, 2010


Mod note: Fixed a problem with a link. Carry on.
posted by cortex (staff) at 7:33 PM on September 5, 2010


I like this droopy moustache propeller example. Also cubics.
posted by Nelson at 7:35 PM on September 5, 2010 [1 favorite]



What's worse is that I'm having trouble wrapping around why this does what it does


The simplest explanation I've heard is that it records by "drawing" pixels from top of frame to bottom. But when something is moving fast, the drawing can't keep up, and the object ends up moving partly into its future position before the frame is done rendering. Thus it looks "bent" in the direction it was moving. I think.
posted by drjimmy11 at 7:36 PM on September 5, 2010


Yeah the helicopter one is not a rolling shutter effect - the RPMS of the rotor and the FPS of the camera are just synced.
posted by Threeway Handshake at 7:39 PM on September 5, 2010


(or in case, since the propeller blades are moving down towards the camera, and since I imagine the blades move faster then the center thingie, they appear to "fall off" downwards.)
posted by drjimmy11 at 7:39 PM on September 5, 2010


aka slitscan
posted by phrontist at 7:43 PM on September 5, 2010


Also known as jelly effect or skew. It bugs the hell out of me.
posted by BlackLeotardFront at 7:46 PM on September 5, 2010


What's worse is that I'm having trouble wrapping around why this does what it does....once I know, I can play around with it. But it's killing me that I can't just look at it and say "well, it's because...."

Does this help?
posted by Rhomboid at 7:52 PM on September 5, 2010 [32 favorites]


This is just as cool, but it doesn't take place in the air. Not exactly NSFW, but be ready to explain it.
posted by randomyahoo at 8:06 PM on September 5, 2010 [2 favorites]


phrontist nailed it... slitscan.
posted by bz at 8:10 PM on September 5, 2010


This is just as cool, but it doesn't take place in the air. Not exactly NSFW, but be ready to explain it.

Woah, a real-life Sarlacc.
posted by Forktine at 8:56 PM on September 5, 2010


Since my hands shake so much its pretty much always get blurry photos, maybe I should just try for rolling shutter shots on everything I photograph.

Dear AskMe: How do I create a secure mobile bungy unit that lets me throw my phone around without inevitably dropping it and watching it shatter, along with my soul?
posted by Dandeson Coates, Sec'y at 9:16 PM on September 5, 2010


'its'? No, 'I'. My mother would be so disappointed.
posted by Dandeson Coates, Sec'y at 9:18 PM on September 5, 2010


My motorcycle mama picture shows this effect. I never knew it had a name.
posted by Blazecock Pileon at 9:30 PM on September 5, 2010


bwg: "The Rolling Shutter Effect : a mobile phone camera is fairly quick, but when the objects you are recording move faster than the scan rate, cool things happen. "

Either that, or Boeing just developed a four-dimensional propeller.
posted by Rhaomi at 9:48 PM on September 5, 2010


A fairly simple live version of this effect can be seen by viewing things through a box fan. The chopping effect of the fan blades will effectively create a "moving shutter" for your eyes.
posted by IAmBroom at 10:10 PM on September 5, 2010


It's a lot scarier on a helicopter.

Oh, man. My wife and I honeymooned in Hawai'i and took a puddle-jumper plane between islands. I though I'd get a couple shots of the right-side nacelle and prop while in flight. My camera's preview LCD did just this, perfect sync.

Of course, I didn't realize that's what was going on for a few very long moments; instead taking what the screen was showing me as (horrible, horrible) reality. Just enough for the instant adrenaline and cold sweat. I started when I noticed it, but everyone else seemed fine. I definitely did a double-(triple-quadruple)-take.

After that it was neat.
posted by speedo at 10:13 PM on September 5, 2010 [1 favorite]


Don't finish line cameras use some variation on this, intentionally?
posted by smackfu at 6:58 AM on September 6, 2010


If you want to experiment with this effect and have a webcam and a computer with linux on it lying around try effectv, specifically the 1DTV effect. It basically simulates a very slow-moving rolling shutter, so you can experiment with different kinds of movement.

And even though I cannot find it right now I distinctly remember a music video using something like this, too: when people turned around their head would have finished turning and then the rest of their body would follow - it gave them a disturbing, rubbery look. If only I could remember... (David Byrne? Muse?)
posted by PontifexPrimus at 7:31 AM on September 6, 2010


This also works on people.
posted by Evilspork at 9:13 AM on September 6, 2010 [3 favorites]


Here are some shots I took with my old iPhone 3G, which was particularly prone to the effect, especially if you deliberately moved the phone during the exposure.
posted by w0mbat at 2:51 PM on September 6, 2010


This is nothing new, although the videos are neat.
posted by TedW at 3:34 PM on September 6, 2010


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