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Panning camera across still image too jerky

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Neil SicktermanPanning camera across still image too jerky
by on Apr 30, 2011 at 5:29:29 pm

Compositing an animated short film. When doing panning null-object/camera moves across still images (The majority of the film will use this effect), I am getting an overall subtle, but noticable jerkiness during ram preview (almost as if I were in photoshop and using my curser arrow to pan around the screen). Don't think my computer is the issue (dual core I5, 500 GB Harddrive, 3.2 GHz Processor Speed/core, 8 GB RAM).

I have tried turning on motion blur switches, easing in/out of the keyframes(still playing with speed/influence settings but doesn't effect the jerky camera pan).

When the null object/cammera curve is a compound curve, The jerks are even more abrupt at the frames where the camera/null object curve starts a transitions from one curve to the next.

I wonder if there are certain file types that are best for smooth pans or if the sizes are the factor. I have tried both small and huge file sizes as well as .psds, .jpgs, and .pngs.

Any ideas?


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Walter SoykaRe: Panning camera across still image too jerky
by on Apr 30, 2011 at 6:07:27 pm

First, double-check while previewing that RAM preview is running in real-time. (There are a few scenarios that can cause RAM preview performance to suffer, but it's always indicated in the Info panel if this happens.)

As long as it's a supported import format, AE doesn't care about the file type or size of the file. Smaller or larger files will not affect the output of renders or RAM previews -- but may affect the quality of your photo. You're fine using the least-compressed photos you have access to.

As a side note, you may reduce your render times and your RAM requirements by pre-scaling really large images down, but using larger or smaller photos will not affect any judder you may be seeing.

You may be seeing normal panning judder -- this will happen if your pan is too fast for your frame rate, both in After Effects and physical cinematography. What frame rate are you working at? How big is the camera move causing the judder?

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Neil SicktermanRe: Panning camera across still image too jerky
by on Apr 30, 2011 at 6:56:53 pm

I am working in 24p, panning relatively slow (an establishing shot). The still is approximately twice as wide as the screen size and I am panning across the entire still from left to right (begining on the left 1/2 and ending on the right 1/2 of the overall width of the image).

Conceptually I understand what your saying about my frame rate vs. pan speed. Seems that 24p might exagerate that phenomenon. Technically, I don't know exactly how to fix other than slowing the shot even more (which could make the shot too long in time length and become boring to watch). Is there an equation or rule of thumb about frame rate vs. pan speed or pan distance? Or any tricks to get around the problem?


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Tudor "Ted" JelescuRe: Panning camera across still image too jerky
by on Apr 30, 2011 at 10:32:21 pm

Few things to try that always worked for me:
Fast blur on the image- .3 to .7 will do.
Apply motion blur- you already did that it seems.
Pre-render the background only with the camera move as interlaced footage and then import that back and de-interlace it using interpret footage. Use that as your background as a 2d layer.

Tudor "Ted" Jelescu
Senior VFX Artist


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David GhastRe: Panning camera across still image too jerky
by on May 1, 2011 at 2:11:39 am

I ran across this problem, though i was panning across video. Pan and scan shots are typically pretty short and only really exist to provide some motion to what would otherwise be a boring still. They werent meant to reveal stuff, as that would take too long and its a pretty boring thing to watch regardless.

As for the judder, AE does that alot, render it out to h264 and see how it does.


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Walter SoykaRe: Panning camera across still image too jerky
by on May 1, 2011 at 12:49:00 pm

[David Ghast] "As for the judder, AE does that alot, render it out to h264 and see how it does."

I'm not sure what you mean here -- AE doesn't create unnecessary judder.

AE's default lossless output module generates an intermediate file that is designed for additional post-production use, not direct playback. These files are generally huge, and very few computers can play them back in real time without stuttering For more, see this Adobe FAQ [link]: Why is my output file huge, and why doesn't it play back smoothly in a media player?

I don't think that Neil is having a playback problem, since he mentioned it was also juddering during RAM preview. I also don't recommend rendering directly to H.264 from AE; you'll get better results from a separate compression application which uses multi-pass encoding.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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David GhastRe: Panning camera across still image too jerky
by on May 1, 2011 at 7:16:23 pm

Like i said, AE judders alot on ram preview, despite ones system. We're talking about adobe here, not autodesk, what do you expect?


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Walter SoykaRe: Panning camera across still image too jerky
by on May 2, 2011 at 2:59:04 am

[David Ghast] "Like i said, AE judders alot on ram preview, despite ones system. We're talking about adobe here, not autodesk, what do you expect?"

RAM preview generally works very well.

If you see stuttering (dropped frames) on RAM preview, what does it say in the info panel? Have you tried temporarily disabling video preview or color management?

I have also seen tearing during RAM preview, but this was caused by the graphics card. Switching cards eliminated the problem.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Dave LaRondeRe: Panning camera across still image too jerky
by on May 3, 2011 at 4:09:31 pm

[David Ghast] "We're talking about adobe here, not autodesk, what do you expect?"

Then go out and get yourself Flame for Mac, pay for the hardware mandated by Autodesk, pay the annual $15k software leasing fee and your life instantly will get better.

Oh, but you can't AFFORD that pricey software? Then I suggest you stick with Adobe and quit your bitchin'.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Neil SicktermanRe: Panning camera across still image too jerky
by on May 1, 2011 at 7:20:13 pm

Walter, Ted, & David,

Thanks for your interest and recommendations. I did some research on the subject of judder and I now know its a 24p chronic issue with medium speed zooms and pans. I will definatly experiment with the techniques you suggested in addtion to planning my shots to avoid the issue in the first place (faster/slower camera moves, purposeful camera bounce, moving subjects/objects to steal the focus away etc).

Cheers to this site again for being so helpful.


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Walter SoykaRe: Panning camera across still image too jerky
by on May 2, 2011 at 2:51:18 am

Hey Neil,

I'm glad I could help point you in the right direction.

I like to try to deal with judder by tracking the subject while panning, so the subject moves less on-screen and exhibits less judder. Of course, judder will still happen elsewhere in the frame (where the pixels are moving faster), but because the viewers are watching the subject, they often don't notice.

Good luck with your project.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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