Shoot Fast Shutter for Post Stabilization & Slow Motion? Then Add Motion Blurr?

Discussion in 'Digital Video' started by Chris7, Nov 10, 2010.

  1. Chris7 macrumors 6502

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    Lost in Thought
    #1
    Wondering what shutter speed I can shoot and still add convincing motion blurr?

    I usually shoot at 24 fps; shutter of 1/48.

    Can convincing motion blur be added in post if I shoot at 1/200?

    Using "Motion Blur" in the FCP "Motion" tab, what parameters are recommended to recreate the look of 24p shot at 1/48
    (1) If I shoot at 1/100? (one stop fast)
    (2) If I shoot at 1/200? (two stops fast)

    Are there faster rendering plug-in's that add motion blur (compared to the motion parameter built into FCP)?
    I think the folks that makes Twixter makes one?

    Thanks for your time,

    Chris
     
  2. LethalWolfe macrumors G3

    LethalWolfe

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    Jan 11, 2002
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    Los Angeles
    #2
    Not in front of FCP right now but I believe the motion blur tab in FCP only adds blur when you move the video frame using the attributes in the Motion tab (scale, x/y axis, rotation). It doesn't add blur to what is going on in the video itself.


    Lethal
     
  3. faustfire macrumors 6502a

    faustfire

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  4. Chris7, Nov 11, 2010
    Last edited: Nov 12, 2010

    Chris7 thread starter macrumors 6502

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    #4
    What Render Speeds with Reel Smart Motion Blur (FCP Fx Plug version)

    Thanks. Humm, this is the one made by the folks that make famous "Twixter" and "De:Noise." Wish I could contact them by some way other than just e-mail, though.

    1. Does the motion blur look natural?
    2. What render speeds are you getting with Reel Smart Motion Blur? Could you list the graphics card you're using (I assume you have the FCP Fx Plug version)?
    3. If you're using the AE version, does the plug-in render faster with "Render Multiple Frames Simultaneously."

    (Either way, it looks like I'm past due for a new computer -- still on a MacBook Pro with 128MB VRAM).

    It appears to do something to video that it is not animated around the screen with the Motion tab. But it does not look like anything resembling natural motion blur.

    It would seem that shooting at a faster shutter and adding motion blur in post would be a somewhat common workflow (I see advertisements that constantly change between real time and slow motion in the same cut). But I've not read about this.

    Any suggestions are welcome.

    Thanks,
    Chris
     
  5. handsome pete macrumors 68000

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    Aug 15, 2008
    #5
    that's time remapping.
     
  6. Chris7, Nov 13, 2010
    Last edited: Nov 13, 2010

    Chris7 thread starter macrumors 6502

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    #6
    Adding Motion Blur to Real Time Part of Time Remapped Clip

    I realize I was not totally clear...

    (Stu Machwitz said a shutter of 1/120 for "cranking" to 60fps to be played back at 24fps, so I inferred the rest from there).

    I am talking about (variable) time remapping when I refer to advertisements that go from slow motion to real time in the same shot. My understanding is, in order to get "good" (not blurry) slow motion, you have to shoot a faster shutter; and this shutter speed would make footage look choppy if played back in real time (not slow motion).

    I understand this to be the case, whether the slow motion is done by cranking (and then don't use all the frames when the clip is sped up to real time) or in post (by adding frames to the slow motion part with Twixter, etc.). I think the standard is to shoot a stop faster shutter for 2x slow motion, two stops for 4x slow motion, etc.

    I had assumed that, if the slow motion was slow and clear, then the clip was shot at a faster shutter than would be ideal for the part of the clip that is played at regular speed. So motion blur would have to be added to the real time part to prevent it from looking choppy.

    Please correct me if this is inaccurate. Again, I have not read about this workflow, and I'm just a hobbyist.

    And any help or links are welcome.

    Thanks,
    Chris
     
  7. KeithPratt macrumors 6502a

    Joined:
    Mar 6, 2007
    #7
    Not sure how much it's used nowadays, but the old fashioned way would be to shoot an in-camera ramp. This would be done on a film camera with a fixed mechanical shutter, meaning the shutter angle would stay constant irrespective of frame rate (a 180° shutter would be 1/120 at 60fps, 1/48 at 24fps, etc.).
     

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