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I shot some footage on a Sony a7s at 59.94 fps so that I could slow it down in post to achieve a smoother camera movement. But when I interpret it to 23.976 fps in Premiere, it looks like it's dropping frames. It looks super glichy and terrible. When I scrub through the interpreted clip frame by frame, it looks like it has duplicated every frame. Each frame is held for the length of two frames. What can I do to slow the footage down so that it looks smooth?

I am especially confused because I've used this technique in the past with footage shot on a Canon Mark III and footage recorded through a Shogun. When I interpret that footage to 23.976, it looks perfectly smooth.

Things I have tried with the Sony footage, none of which worked:

  • Interpreting to 23.976
  • Dragging 59.94 clip to 23.976 sequence and slowing it down to 50%
  • Frame blending
  • Opening the clip in After Effects and interpreting to 23.976
  • Selecting "Pixel Motion Blur" on the interpreted AE clip

I am using Premiere Pro CC 2015. Any help would be much appreciated.

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I figured out the problem. My shutter speed was set too low. Turns out it needs to be double the frame rate in order to achieve a smooth motion when interpreted to 24 fps. Should have thought of that before I shot. Oh well. Lesson learned.

  • You can accept your own answer. – kazanaki Jul 17 '15 at 8:58
  • @kazanaki You have to wait 24 hours to accept it. – mcography Jul 17 '15 at 15:56
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Since this has worked with Canon footage in the past, my best suggestion would be to import your a7s footage into a 59.94 fps sequence in Premiere, export that sequence (in 59.94) in a universal format like H.264, then re-import that clip to Premiere and try slowing it down to 23.976. My guess is that Premiere isn't playing nice with whatever codec/format the a7s footage was shot in.

  • Thanks for your suggestion. I actually figured out the problem though. My shutter speed was set too low (I think around 1/50). Turns out it needs to be double the frame rate in order to achieve a smooth motion when interpreted to 24 fps. Lesson learned. – mcography Jul 16 '15 at 16:16
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    @mcography yes, 1/120 is the typical shutter for 60p slow mo. It's always 1 over double the frame rate for 180 degree shutter. But there are some ways of changing this depending on the look you are going for... I suggest you check out red.com/learn/red-101/shutter-angle-tutorial – Alex Jul 17 '15 at 17:56
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Question is pretty old, but problem still actual. You can reduce fps from 60 only to 30 fps without framedrops. In that case Premiere properly reduce fps. If you need final result in 24 fps you should shoot in 50 fps. Hope it would help for someone.

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