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Strange Jello effect on 120 FPS RED footage. Help!

J

Justin McAleece

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Here is a clip that I shot for a short film last week that has a very obvious and weird warping effect to it.

http://vimeo.com/22669895

Here are some specifics:

120FPS, 2K 2:1, Redcode 27, Original Mysterium Sensor, 23.0.6 firmware (I think)

Canon 70-200 Lens

Locked-off static tripod shot (completely still)

Temperature 65-70 degrees (not hot enough nor far enough away to have rising heat interference issues)


We watched the clip during playback while on location and everything seemed fine. I really felt like I would've noticed such an extreme effect. This issue is present in several other shots but only when at 120FPS.

WTF? PLEASE HELP
 
I'm 99% sure that there's no way the camera was still. And what was the shutter speed? Faster the shutter, the more noticeable the rolling shutter skew.
 
It's possible it was the IS but I thought I turned it off and I also used the IS on all sorts of footage the rest of the shoot while at 4k 24 and there were no issues with it.

I promise you - the camera was completely still. The R3D is like a minute long and it is there the entire time. Shutter speed is 240 to stay 180 degrees at 2k.

To reiterate also - I swear that we watched it back multiple times on the 17" panny and it looked fine. I'm so confused.
 
it does look like some kind of vibration though. A Squall that causes the tripod to vibrate maybe?
 
Even if it were a wind vibration issue, this is much more than I've ever seen. It reminds me of bad GH1 footage.
 
Jeff Kilgroe said:
I'm 99% sure that there's no way the camera was still. And what was the shutter speed? Faster the shutter, the more noticeable the rolling shutter skew.
Click to expand...

Yeap. No doubt the camera was not still. That is the effect when you use image stabilization on the lens or in post, like using smoothcam in FCP. Using longer lenses on 2k mode made the problem more notorious on the Red One .
 
Optical Image Stabilization was my first thought, also, but why would it have been working so hard if the camera was still? IS senses motion and corrects...

Missing stuff it on location happens, I'm afraid...

It does track that you wouldn't necessarily see IS problems on 24fps footage - the IS motors are pretty quick and you might need to be rolling at 120 to create jello like that.

Were you using a Birger mount?
 
I've shot maybe 100 hours of footage on that lens with the IS on in sometimes really bad situations (vibration-wise) like having it on the floor of an SUV driving down a gravel road at 200mm. I've never had it do anything similar to this. It's a little insulting that people keep telling me the camera was moving when I know that 100% unequivocally it was not.
 
Mark Wilkinson said:
Optical Image Stabilization was my first thought, also, but why would it have been working so hard if the camera was still? IS senses motion and corrects...
Click to expand...

Thinking back to some stuff I was taught, I'm sure I'd heard that having IS turned on when you didn't need it - i.e. on a solid tripod! - was a Bad Idea; the IS system can get confused and 'hunts' slightly, overcompensating for the most minor vibrations that wouldn't show in the image, as it looks for something to correct, and actually introducing vibration in the process.

Either way, I remember the message very clearly - turn IS *off* if you're on a tripod!

Mike
 
Justin McAleece said:
I've shot maybe 100 hours of footage on that lens with the IS on in sometimes really bad situations (vibration-wise) like having it on the floor of an SUV driving down a gravel road at 200mm. I've never had it do anything similar to this. It's a little insulting that people keep telling me the camera was moving when I know that 100% unequivocally it was not.
Click to expand...

The camera may have been rock solid but see my post above; I find it easy to believe that an inadvertently activated IS system actually introduced vibration within the lens BECAUSE the camera was rock solid.

If I were you I would try to repro the problem; shoot again, IS on and IS off, it would drive me crazy if I didn't track down the cause of this.

Mike
 
Mark Wilkinson said:
the IS motors are pretty quick and you might need to be rolling at 120 to create jello like that.
Click to expand...

Correct. Also if the camera is completely still with a zoom you will need good head and good legs. Light wind can be a big problem if you do not use the right support system.
 
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