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Shooting a "first person" sequence with minimal possible motion blur


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#1 Duca Simon Luchini

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Posted 24 June 2016 - 01:07 AM

Hi everybody,

I'd like to shoot a "first person" sequence with minimal possible motion blur because we have to make an extensive motiontracking (Matchmoving) of the entire sequence.

So, I thought would be a good idea to shoot at a "normal" frame rate ( (24 or  25 or  30 fps)  but acting the scene very slow and than accelerate the sequence in post.

Or , maybe, I should shoot with 60 or 120 fps (I don't have a Phantom....) to try to avoid motion blur.

Any other suggestions?

 

Many thanks for a reply.

 

 

 

 


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#2 Tyler Purcell

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Posted 24 June 2016 - 01:17 PM

You can avoid motion blur by simply increasing the shutter speed (decreasing shutter angle). Increasing frame rate can also help, but going from 24 - 30 may not help enough.

I shoot at 45 deg shutter all the time and my stuff has very little motion blur @ 24fps.
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#3 Duca Simon Luchini

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Posted 25 June 2016 - 12:48 AM

Hi Tyler,

normally shutter angle should be double of the Frame rate, right? So if I shoot at 24 fps, I should  have a 48° shutter angle. You used 45°... it seem to be a very small difference.


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#4 Tyler Purcell

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Posted 25 June 2016 - 02:40 AM

Well, it's a digital camera, so it can run shutter angles that film cameras can't. Most digital and film cameras run 180 degrees stock.

A high speed camera would help resolve the motion blur issue, but at an added cost.
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#5 evanwalsh

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Posted 25 June 2016 - 09:07 AM

Hi Tyler,

normally shutter angle should be double of the Frame rate, right? So if I shoot at 24 fps, I should  have a 48° shutter angle. You used 45°... it seem to be a very small difference.

 

I think you might have gotten it mixed up, a 180º shutter angle would translate to 1/48th of a second exposure time. If the camera you're using doesn't have a shutter angle option, you could turn it up to 1/144th or 1/240th exposure time to lessen the motion blur. Spike Lee's 25th hour has some high shutter speed sequences and the movement of the actors is very sharp if that's what you are going for. 


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#6 Duca Simon Luchini

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Posted 25 June 2016 - 09:27 AM

 

I think you might have gotten it mixed up, a 180º shutter angle would translate to 1/48th of a second exposure time. If the camera you're using doesn't have a shutter angle option, you could turn it up to 1/144th or 1/240th exposure time to lessen the motion blur. Spike Lee's 25th hour has some high shutter speed sequences and the movement of the actors is very sharp if that's what you are going for. 

Ah, ah, you are right! I confused my self, anyway is was the meaning...

So, it could be ideal to use faster time exposure with 24, 25 or 30 fps. And of course, if I shoot at 60 fps or 120 fps, I should use even more faster shutter speed as 1/1000 or more (?).


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#7 Tyler Purcell

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Posted 25 June 2016 - 12:47 PM

Yea, you can use a super high shutter speed for sure.
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#8 Maximilian Motel

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Posted 11 July 2016 - 10:08 AM

You could certainly use faster shutter speeds (like the 45° angle in Saving Private Ryan), but if motion tracking is your concern, I feel like modern software should be fine with motion blur as well. It'd probably be harder to add "correct" motion blur in post than to shoot and track with it straight out of camera. (Example with Mocha: https://www.youtube....h?v=ZGDlW1QeY3c).


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#9 Duca Simon Luchini

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Posted 12 July 2016 - 01:25 AM

You could certainly use faster shutter speeds (like the 45° angle in Saving Private Ryan), but if motion tracking is your concern, I feel like modern software should be fine with motion blur as well. It'd probably be harder to add "correct" motion blur in post than to shoot and track with it straight out of camera. (Example with Mocha: https://www.youtube....h?v=ZGDlW1QeY3c).

Of course, but the problem is to do a global matchmoving and not a single object tracking as in you example.


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#10 Jon Kline

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Posted 18 July 2016 - 04:51 PM

I've done some work that was match-moved with a 1/48 shutter, but not handheld. I would do a test shot at 1/48 and see if it lines up easily. If you use a prime lens and are smart about keeping some trackable points in the frame, it probably won't be an issue.


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