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CMOS Rolling shutter


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#1 Matteo Cocco

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Posted 25 February 2011 - 09:40 AM

Hello everybody,

I'm prepping for a feature film to be shot with the Red One.

We've done some test shooting in September and had some worries concerning the rolling shutter. The whole opening sequence is shot from a moving Train and we don't really like how objects in the foreground look.

I did some research and found out there are many Plug-ins to remove this Jellocam effect. I'm just wondering how good these software are for a theatrical release.
Do you have any suggestions or ideas?
Thanks a lot!
Matteo
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#2 Phil Rhodes

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Posted 25 February 2011 - 09:50 AM

A perfect fix is impossible. I've seen somewhat-convincing results from The Foundry's Rolling Shutter plugin, but the results will invariably be somewhat dependent on the image content to begin with. Shoot tests.

P
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#3 Adrian Sierkowski

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Posted 25 February 2011 - 09:53 AM

Might we worth it, if you really don't like the effects, to rent some other system for the opening. I'm always wary of post tools but there are some tools out there which I've tried to use with my EX1, similar rolling shutters, sometimes it works, other times it doesn't.
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#4 Matteo Cocco

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Posted 25 February 2011 - 12:30 PM

Thanks for your help. We were actually thinking of using another camera system for that sequence....
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#5 John Sprung

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Posted 25 February 2011 - 01:27 PM

There are two problems created by the rolling shutter:

1. Jell-o-vision: The bending of objects that move horizontally can be fixed in post by pretty much any effects system. The one thing you need to keep in mind is that straightening up the contents of the frame will tilt the side frame lines. So, you'll have to crop and lose a little at both sides to get them vertical again. Frame those shots just a little loose to give yourself room to crop.

2. Strobe Cutoff: Strobe lights actually catch the shutter edge in frame, producing frames that have a sharp horizontal boundary between when the strobe was emitting light, and when it wasn't. If you get stuck with things that strobe, you could expensively hand paint each frame, or do a cheap substitution of a flash frame. The better course is to avoid strobe sources, and if you must, do hand-made fake strobes in post. They'll be easier and better than the hand-made fixes to the cutoff frames that come from real on-set strobes. Shoot a little reference burst with a constant source in the strobe position if you want a guide to do the hand work.




-- J.S.
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#6 David Mullen ASC

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Posted 25 February 2011 - 01:55 PM

Some people are a lot more sensitive to the jello-vision problem than others... I've never noticed that problem with Red One's, and we had this huge car chase sequence in "The Chicago Code" shot partially on M-X Red One's. I'm sure the effect is there if you looked for it, but I've never noticed it.

The strobe light problem causing half-frames to see the flash, THAT problem I can see.
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#7 Phil Rhodes

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Posted 25 February 2011 - 02:32 PM

I've been thinking about an LED-based strobe that is syncable with any rolling-shutter camera, through an empirical, observational synchronisation procedure. It can be done.

P
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#8 Kieran Scannell

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Posted 25 February 2011 - 03:19 PM

"empirical, observational synchronisation procedure"

The now famous E.O.S.P. system. The name itself deserves invention! BTW Phil I never thanked you for your advice on the gig I had
in Egypt! Turned out really well! Thanks! I'll send you some footage when the producer sees fit to send me some! sound familiar?

PS. It was a holiday commercial which they have now stopped airing for some reason??
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#9 Phil Rhodes

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Posted 25 February 2011 - 04:44 PM

That's a quick way of saying you turn it on then press the "faster" or "slower" buttons until the split moves out of the display, rather like you'd slip sync on a film camera to match a CRT monitor. It's not rocket science.


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#10 Kieran Scannell

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Posted 25 February 2011 - 05:10 PM

That's a quick way of saying you turn it on then press the "faster" or "slower" buttons until the split moves out of the display, rather like you'd slip sync on a film camera to match a CRT monitor. It's not rocket science.


P


OK! I get it! Like the clear scan on a Digi-Beta?

But I still think "empirical, observational synchronisation procedure" will be the one to make the instruction manual!
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