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Strobelights / Rolling Shutter

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Peter Burger
Strobelights / Rolling Shutter
on Jun 30, 2012 at 1:44:18 am

Any ideas how to deal with rolling shutter issues caused by strobelights from still-cams? You know, when half a frame is overexposed, the rest looks good...

We shot an event at the Munich Filmfestival with a 7D and a 550D today and we were surrounded by photographers. A flurry of camera flashes (Hope this is the right translation - I had to look it up) when certain celebs showed up. No two seconds without a flashlight going off...

Any ideas or suggestions what can be done in post more than welcome!

Thanks in advance!

------------------------------------------
"Tragedy is a close-up; comedy, a long shot." - Buster Keaton

Me on Twitter (english/german)
http://twitter.com/FastFoodVideo


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Steve Crow
Re: Strobelights / Rolling Shutter
on Jun 30, 2012 at 3:29:20 am

Peter I don't think there is anything you can do to correct this - the camera is capturing exactly what happened. In theory, if you removed every other frame (the frames filled with a flash) and then replaced that frame with a copy of the one before or after it, then all the flash frames would be removed but I still think it would look weird (slow motion? and off-sync)

There are tutorials online for ADDING flash effects to your video but I don't think there can be any on removing them...maybe there is a creative work around I haven't thought of however, let's hope! :-)

Steve Crow
Crow Digital Media
http://www.CrowDigitalMedia.com


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Peter Burger
Re: Strobelights / Rolling Shutter
on Jun 30, 2012 at 2:00:01 pm

[Steve Crow] " I don't think there is anything you can do to correct this - the camera is capturing exactly what happened"

That's what I thought as well... We discussed the problem before the shoot, but had no idea how to solve it. I hoped that - like in other projects - I would be able to "cut around" the flashes most of the time, but no chance here ...

I thought about maybe stylizing the footage if everything else fails. Luckily this is not supposed to be a documentary but more like a "music-video-style mood-clip sort of thing"...

We had to capture the DJ-performance of an internationally very well-known musician, producer and film-composer and create a promo-clip for him.

[Steve Crow] "In theory, if you removed every other frame (the frames filled with a flash) and then replaced that frame with a copy of the one before or after it, then all the flash frames would be removed but I still think it would look weird (slow motion? and off-sync)"

That's basically a great idea. Sync is not a problem. We won't use the audio anyway, but get a completely different track. Strobing could be a problem, because of the missing frames... Hmmm... Maybe in After Effects: Remove the frame and interpolare the gap... Could work for single flashes, but we had a "thundestorm"...

But I think this could be a solution for a couple of shots. If I had to do all of them... Don't even want to think about it ;)

Thanks a lot for the suggestion, Steve! Much appreciated! I'll definitly play around with that!

Edit: Just want to add: The flashes per se don't bother me at all. It's the "half-frame" issue... Maybe (for selected shots): Mask the correctly-exposed part of the picture out and increase exposure for that part in post... Will try that as well

------------------------------------------
"Tragedy is a close-up; comedy, a long shot." - Buster Keaton

Me on Twitter (english/german)
http://twitter.com/FastFoodVideo


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