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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Rolling Shutter

Jannard said:
We have pointed this out to every DP (and VFX god) that was interested in using RED on features. So far, no one has seen it as a problem.
Jim
Click to expand...

I've followed the story on the evolution of the RED's rolling shutter as much as possible in this forum and others. Your words are encouraging.

Please understand, for some people this issue is a 0% concern, for others who do VFX it might be closer to 50%.

The buck stops with me on the success of a shot requiring motion tracking, therefore I have more concern than someone who just shoots hot looking models all day long!
 
My bet is that by the time you get the shot moving fast enough to produce shutter smear, the motion has already made it pretty difficult for an audience to critique the image / notice if your plate doesn't match up 100%.
 
The Phantom HD & 65 also have rolling shutters (really fast ones) and these cameras are used for VFX work a lot. I have to tell you that except for some lightening bolt shots (real lightening), this has been a total non-issue. I would expect the same for the RED.

Mitch Gross
Abel Cine Tech
 
mylrea said:
My bet is that by the time you get the shot moving fast enough to produce shutter smear, the motion has already made it pretty difficult for an audience to critique the image / notice if your plate doesn't match up 100%.
Click to expand...

I'm more worried by a small amount of skew at slower speeds. At some point you can fake/smudge anything, it's motion tracking at "normal" speeds I'm worried about, where your tracking needs to be accurate across the whole image area.

As an aside, (and someone correct me if I'm wrong) my understanding is that shutter speed and rolling shutter skew are un-related. You can crank up the shutter speed to, say, 1000th and the image will still have the same amount of skew as it would have at 1/48th, just be less masked by motion blur.

Film of course has skew, but only at the attack and retreat of the shutter across the image plane. The middle half of the exposure is "global shutter".

I did an animation months ago of a "worse case" subject to illustrate;

http://ftp.datausa.com/imageshoppe/outgoing/SHUTTER_STUDIES/FILM_SHUTTER_SKEW_CLASSIC.mov

In practice, the shutter is out of focus as it travels across the image, limiting the impact of the skew, and the angle of attack varies depending on the build of the shutter, but the concept is sound.
 
Mitch,

How many Reds have Abel Cine Tech ordered and when will they be available for
rental?
 
Claudio's report (before he pulled it) on his experiences with the RED ONE mentioned vertical compression/expansion (i.e. of buildings) as the camera bounced up and down on some mobile shots.

Would build 12 address this as well?

-Steve
 
LighthouseMEdia said:
While I haven't seen skew in any of my shoots I have been more frustrated with the split screen artifcating by bright flashes of light etc...Is there any work around for that currently, or is that just an inherent problem we will learn to deal with due to CMOS technology?
Click to expand...

FYI, here's what it looks like on film... this is from the opening sequence of Pitch Black, which has what appears to be synced and un-synced strobes going off...

PitchBlack_strobes.jpg
 
Jannard said:
I posted on this topic several months ago (use the search). We use a rapid reset sensor system which is much faster than a typical CMOS rolling shutter. It is a bit slower than film so it is easier (not much) to induce skew with RED than with film. But it is MUCH better than a standard rolling shutter.

We have pointed this out to every DP (and VFX god) that was interested in using RED on features. So far, no one has seen it as a problem.

Jim
Click to expand...

I'll look a little harder this time.

Absolutely agreed. This kind of thing shouldn't be a problem. You have to basically do a whip pan to notice it... but it is good to be aware of the limitations of the tools you are using.

Glad to be able to discuss these issues and get feedback from people who care.

Dylan Macleod, CSC
Toronto, Canada
www.dylanmacleod.com
 
ibloom said:
But Jim Arthurs, until you've actually run a test match-move from Red footage, why assume the worst.

Ok, gotta get back to shooting hot models, this shit takes all day.

IBloom
Click to expand...

I wouldn't say I'm assuming the worst. I'm actually very optimistic. If I was assuming the worst, I'd have pull my reservation ASAP the moment I learned the RED had a rolling shutter and called it a day, as motion tracking is a huge chunk of what I do with the footage I shoot, and I can't afford to take a step backwards in this area even if I'm taking several big steps forward in others.

I'm the kind of guy who likes to quantify things. "It's pretty good" or "It's pretty bad" are a bit vague for me. As I said in the very first post I did in this thread, to know a thing is to understand a thing. That's all. I'm fortunate to be able to test this out in a week or so and then get on with life.

Now get back to those models. They're tired, the lights are hot, and the whip cream isn't gonna lick itself off... :)
 
Well. . . I WAS going to be shooting some footage on my upcoming feature to a strobe light as the sole illumination. I guess I won't be doing that, will I?

:-(

Stephen
 
We use a rapid reset sensor system which is much faster than a typical CMOS rolling shutter
Click to expand...


stephen, jim told us red is a different thing, so keep patience and test it.

it is right, we have equal "problems" with filmcameras.
otherwise, the effect on the ex1 footage is dramatically bad.
 
Stephen Pruitt said:
Well. . . I WAS going to be shooting some footage on my upcoming feature to a strobe light as the sole illumination. I guess I won't be doing that, will I?

:-(

Stephen
Click to expand...

That's no problem Stephen, use the genlock output on your camera to sync the strobe so that it doesn't pop during the readout period of the camera. You would want to do this on film as well.

Plus some people think the shutter artifact looks cool, judge for yourself:
http://web.mac.com/fini1/iWeb/Site 135/4k Red Camera.html

IBloom
 
David Birdy said:
Mitch,

How many Reds have Abel Cine Tech ordered and when will they be available for
rental?
Click to expand...

I'm not at liberty to say and honestly, no one really knows when they will have their Reds!

Mitch Gross
 
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