September 7, 2015 at 6:19AM

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jerky 25p GH4/3 footage what i am doing wrong ?

Hello i am fighting with 25p jerky footage shooted at 180d or 1/50 shutter. Jerkiness is even in steady shoot only with character moving - there is no motion blur. Look please at this - shooted at 24p with 180d shutter speed this scene, smooth as ... https://youtu.be/U-F3LOZqMKs?t=4m3s and look at this - shooted at 25p 180d shutter https://youtu.be/8zJTbxI_4cM?t=20s if my eyes are good and all monitors too, i can say 24p is much smoother - on same shutter rule (180deg.) shouldnt be. Tested gopro with 25p and its smooth too. Is there something in Premiere or on my gpu what i am missing ? For me now 25p is unusable as i can't even shoot a character moving

9 Comments

There is a "golden rule" when panning a camera in film-making that also applies to any other type of motion on the screen, and I think this may be the cause of your 25p "jerkiness"...

To obtain a smooth panning motion when shooting 24 fps footage, every object in your frame should take at least 7 seconds to move from one side of your frame to the other. If you pan faster than 7 seconds the panning motion will NOT be smooth.

With faster shooting frame rates the panning time can be shorter. I can't find any modern panning charts, but here is one for 35mm motion picture cameras. ( I think this would be the same as the Super35 cine format )

http://frontside.de/dls/pan.htm

And here is a short article that discusses panning speeds that includes a video on panning "judder" with the Panasonic GH3 camera...

http://goo.gl/V5dHBB

So you may want to try slowing down the camera movement to obtain smoother looking shots when shooting at 25p.

September 7, 2015 at 12:05PM, Edited September 7, 12:08PM

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Guy McLoughlin
Video Producer
31232

well ok and thank you but sadly i know about these, my problem is in even steady shoots when only character moving in frame - there is no motion blur too and looks jerky - never had this issue before and with 24p i can shoot whatever i want .. with 25p i just cant

September 8, 2015 at 2:05AM, Edited September 8, 2:05AM

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Martin
156

Can you compare to another GH3 / GH4 camera ?

Something sounds off with this.

September 8, 2015 at 7:36AM

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Guy McLoughlin
Video Producer
31232

i cant, i have only mine GH4 and 3 but no more in my town or place near, at evening i can upload unedited 25p short footage

September 8, 2015 at 8:02AM

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Martin
156

Maybe it's just me but the only time I'm seeing stuttering is in some of the fast pans on the 25p footage which is to be expected given the 7 second rule. Is there another spot where folks are seeing stutter?

September 9, 2015 at 10:50AM

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still have no time to upload steady with moving character but for example here, hallway scene: https://youtu.be/OvL9GBfJzfQ?t=12s - why i can do faster pans with 24p (like example above) without jerky-flickering ? again shooted at 25p 1/50s i still thinking that movement should be more fluid with more motion blur with 180 deg. shutter rule

September 10, 2015 at 2:36AM

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Martin
156

That's a fairly fast pan so that is definitely part of it but I don't have an immediate answer for why it seems smoother at 24 than 25 except that perhaps the 1 frame difference in timing is enough to make it more noticeable. Solutions to similar problems in the past have included:

1. Turn off image stabilization on your lens if you have it engaged.
2. Try using Synchro Scan to lower your shutter speed slightly. Some people have expressed positive results as low as 1/43.

If I think of any other solutions, I'll post them.

September 10, 2015 at 12:05PM, Edited September 10, 12:05PM

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That happens to me sometimes, at 25p 180d, but mostly while editing and not so much in my final output. So could it be that your render settings are off somehow?

/Per

September 11, 2015 at 6:31AM

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avatar
Per Frits
Photographer
145

Dont think its about render settings - using the same for ages (for 24 or 25p). Problem maybe causing mega o.i.s. on lense BUT there is something odd cause i must switch it off even in camera body settings not only switch on lens - now with both off looking good so far but i must give it a test. thank you

September 14, 2015 at 2:48AM

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Martin
156

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