How to smooth camera pan jittering

[megang11931280]

I'm trying to pan horiztonally across a video, but all of my images seems to jitter in the export and its quite jarring on the eyes.  its 1920x1080 and it has to be 24fps. Motion blur doesn't help, as the camera movment isn't fast enough to show any sort of blur.  How do I fix this so that it moves horizotnally smoothly? I've read about subpixels, but none of the expressions I see on the internet seem to help.

[Martin_Ritter]

Can you provide a sample of the jittering? I guess the relation between camera movement, fps and shutter angle is misfitting in your case.

*Martin

[Mylenium]

Well, what's not there isn't there. If the movement is too slow it will always stutter, especially on 24 FPS. Simple math/ physics. If native motion blur doesn't help, try effects like directional blur, CC Force Motion Blur or Timewarp. Still, it won't defeat the underlying issue, only obfuscate it.

Mylenium

[Mike_Abbott]

",,,Motion blur doesn't help, as the camera movment isn't fast enough to show any sort of blur."

Just in case you're not aware of it, you can adjust the amount of motion blur applied to a comp:
Menu: Composition > Composition settings. Advanced tab: try up to 720 in the shutter angle property.

[megang11931280]

Makes sense, thank you for everyones response. My issue is the screen in which the video will play only plays in 24fps, and my idea for the video is to tell a story through one continuous right panning, so motion blur won't give me the crisp look I am looking for. Do you suggest any other solutions? Seems like I may have to scratch my idea.

[Rick Gerard · Accepted solution]

There are critical speeds that every DP worth their day rate should know about. The combination of frame rate and motion can create stroboscopic effects in the video that the human brain cannot process. It has to do with retinal retention and processing speed. The only way to avoid the problem is to change the speed of the movement or change the frame rate. It's commonly called judder. 

The easiest way to fix the problem is to set the speed of movement to precisely an even number of pixels per frame using an expression and also make sure you pick a speed that works for your frame rate. Even moving an even number of pixels per frame can cause problems if the combination of frame rate, movement, and refresh rate in your display is causing judder. There are a couple of articles in the FAQ section of this forum. They are very hard to find now so I'll post a link:  FAQ: Why does horizontal motion stutter (judder) 

You might also search the forum for judder and look at a few other posts. The higher the frame rate, the easier it is to overcome this problem.

[Martin_Ritter]

Thank you @Rick! I was waiting for your post. 😉

[deborah1983]

Hi Rick,

Thank you for your illuminating answer. I'm a photographer, but I've also been working with video for a couple years. I've recently relocated from the US to France, and I'm now having judder issues with my pans (both horizontal and vertical) that I've never encountered before.

When in the US, I moslty shot at 60fps and 1/125 shutter speed with my camera set for 60Hz.

Since in France, I've had to switch to 50Hz, 50fps and 1/50 shutter speed because of flickering issues in poor lighting conditions, but I'm now having juddering issues: all my pans have stroboscopic effects, sometimes worse than other.

I've tried slowing my pans with the 7sec rule. I've also tried shooting at 1/100, 1/200. Nothing works except going back to my old US setting, which poses problems in certain lighting conditions. I don't want to add motion blur because I'm shooting architecture, so it needs to be sharp.

I've also been using this tool  which seems to indicate my settings are correct...

To give more context, I'm shooting with a DSLR Nikon D810.

Any leads? I'm certainly no DP, so pardon my ignorance.

Many thanks in advance to anyone who can help!

[Rick Gerard]

The old ASC handbook used had a Critical Panning Speed section with charts showing the focal length, shutter angle, and panning speed required for smooth pans. When shooting, higher frame rates and higher shutter speeds will not always solve the problem. Motion blur is often your friend. The frame rate of the final video is critical. Fifty or sixty fps movies will give you more options, but you will still get judder at certain panning speeds. Streaming services will also reduce the playback frame rate to save bandwidth, so 60fps video on YouTube may only be playing back at 30 fps.

You can hide judder by following something moving in the frame, by decreasing shutter speed to increase motion blur, or by moving the camera very slowly, then retiming the shot in post, and solving the problem by blending frames.

The refresh rate on your display can also play havoc with panning shots. Fifty fps video played back on a 60Hz monitor will behave differently than the same shot on a monitor with a slower or faster frame rate. Again, motion blur is your friend. The human eye perceives motion between 12 and 24 frames per second, but your brain automatically filters out distractions. 

[deborah1983]

Thank you very much for your prompt response! I appreciate all the leads and will look into them.