bmpcc - videos stutters; what might be the cause?

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Daniel Bănică

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bmpcc - videos stutters; what might be the cause?

PostTue Dec 19, 2017 10:43 pm

Hi @,

I need your advice regarding my videos.
what might be the reason that my video in the attachment "stutters" when I'm moving the camera?
The camera is bmpcc.
The SD card is SanDisk Extreme PRO 64GB (95 MB/s).
The record format is RAW (same thing happens with prores).
The set frame rate is 24 fps.
The shutter angle is 180 (same for 172.8).



Thanks in advance for your help.
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Robert Niessner

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Re: bmpcc - videos stutters; what might be the cause?

PostWed Dec 20, 2017 12:13 am

The reason is that you are moving the camera way too fast for 24fps. What you see as stuttering are the contrasty edges like the wall moving over a dozen pixels per frame.

You can read more and see examples about this here:
http://www.red.com/learn/red-101/camera-panning-speed
Saying "Thx for help!" is not a crime.
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Robert Niessner
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Blackmagic Camera Blog (German):
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Denny Smith

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Re: bmpcc - videos stutters; what might be the cause?

PostWed Dec 20, 2017 1:07 am

Yes, skew artifact from the rolling shutter. As Robert mentioned, you can not pan a Camera with a rolling shutter that fast, or fast at all.
Denny Smith
SHA Productions
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Daniel Bănică

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Re: bmpcc - videos stutters; what might be the cause?

PostWed Dec 20, 2017 7:29 am

I see.
Thanks for your answer.
In this case how was the chasing scene shoot on bmpcc in the last Bourn movie?
I heard they used in that scene bmpcc and there is no stuttering.
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Robert Niessner

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Re: bmpcc - videos stutters; what might be the cause?

PostWed Dec 20, 2017 8:02 am

I am sure there is stuttering in the chasing scene to see if you look closely. The trick is to follow the main movement of a person or object so the stuttering of the rest is masked by our brain.
Try it.
Do a pan in an empty room and a pan following a person crossing the room.

Other tricks: keep fast moving background a bit out of focus by opening up the aperture, increase motion blur by increasing shutter degrees to 360°.
Saying "Thx for help!" is not a crime.
--------------------------------
Robert Niessner
LAUFBILDkommission
Graz / Austria
--------------------------------
Blackmagic Camera Blog (German):
http://laufbildkommission.wordpress.com

Read the blog in English via Google Translate:
http://tinyurl.com/pjf6a3m
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Daniel Bănică

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Re: bmpcc - videos stutters; what might be the cause?

PostWed Dec 20, 2017 10:08 am

Robert Niessner wrote:I am sure there is stuttering in the chasing scene to see if you look closely. The trick is to follow the main movement of a person or object so the stuttering of the rest is masked by our brain.
Try it.
Do a pan in an empty room and a pan following a person crossing the room.

Other tricks: keep fast moving background a bit out of focus by opening up the aperture, increase motion blur by increasing shutter degrees to 360°.

I am so grateful for your valuable advice.

Thank you again.

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