Jello Cam becomes spring cam

W

wheatgrinder

So, in another thread I was talking about gopro hero HD cameras.. I started looking at the footage and noticed something..

I was wondering if they were global shutter and if they had the rolling shutter problem, form much footage it seemed like they did NOT have jello cam.. but then I saw this.. and I think I get it..

https://www.youtube.com/watch?v=P8_SGPCMtK8

My guess is that the sensor is on its side, so what would normally be horizontal JELLO cam, becomes a compress\decompress motion when rotated.. vertical.

Make sense to anyone else?

Jello cam turned on its side is spring cam! maybe?
 
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I have no clue, so it might sound insane (Oh well), but is it maybe like the lens can rotate for optimal mounting or it has a feature to gather the image at various mounted angles, so in effect the sensor’s position might be on it's side as a result? (Or is that what you are saying you suspect, or am I just nuts?)

-Thanks-
 
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I have no clue how to explain what is happening, exactly, but I can tell you that Canon DSLRs do the same thing, and that is not jello. These cameras do not respond well to big bumps and shaking.
 
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I think this look and jello are both manifestation of the problem with rolling shutter.. if you consider whats happening...

rather then the ENTIRE frame being grabbed from the sensor at the same moment (i.e. Global Shutter) the sensor is SCANNED. like a tv, line by line, top to bottom. Sure, its happening really fast, but light is FASTER, and hence when you move the camera quickly, part of that motion takes place during the scan.. some lines have already been scanned before the move, and some are during the move.. all in the same frame.. have a lot of side to side movement and you get jello.. have lots of UP AN DOWN and you springovision..

If this was global shutter, you would just have typical motion blur..

Considering though that it is a VERY predictable math problem, I think software is probably available that will fix jello in post.
 
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wheatgrinder said:
I think this look and jello are both manifestation of the problem with rolling shutter.. if you consider whats happening...

rather then the ENTIRE frame being grabbed from the sensor at the same moment (i.e. Global Shutter) the sensor is SCANNED. like a tv, line by line, top to bottom. Sure, its happening really fast, but light is FASTER, and hence when you move the camera quickly, part of that motion takes place during the scan.. some lines have already been scanned before the move, and some are during the move.. all in the same frame.. have a lot of side to side movement and you get jello.. have lots of UP AN DOWN and you springovision..

If this was global shutter, you would just have typical motion blur..

Considering though that it is a VERY predictable math problem, I think software is probably available that will fix jello in post.
Click to expand...

I just started a thread about how iMovie has a built-in feature to fix jello. And another dude posted that there is some app in AE that does the same. But that's regular lateral jello.

I don't know about this weird vertical shaky-thing, whatever it is. Your theory is at least a possibility, that it is related to rolling-shutter, but I'd have to see more info before I'm convinced. In my dealings with it, it's not so much high-speed vertical movement that causes it, but violent bumps and jolts; it doesn't even have to move much, just with some kind of brut impact.
 
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