Slow Motion

thefilmaddict

thefilmaddict

Veteran
I am going to use the pocket 6k to shoot 120 frames per second. I want to use premiere to make it even slower — a lot slower if possible. Any camera settings I should consider? I was planning on using 180 degree shutter, but could go higher if that helps?

Also, is twixtor necessary? Is it a lot better than premieres slow
Motion?

Thanks.
 
High shutter...Twixtor used to recommend at least 1/2000 or something like that for best results (but I'm not sure how that applies to 120fps as this was like 10 years ago).

But that would be 22° if so...for 120p. (It would be 4° for 24p, lol.)
 
I got some good results with Twixtor back in the day. If I recall correctly, you are supposed to use the shutter speed of your target framerate? (So if you want to slow to 240fps equivalent, shoot at 1/480. If you want to slow to 1200fps, shoot at 1/2400.)

The slow-motion jumping dancer 2 seconds into my reel was actually shot at 30fps on a 7D and Twixtored: https://vimeo.com/38204394
 
1. So when you shoot slow mo with the camera, it shoots 120 frames Per second, but it puts it in a 24 FPS clip. I don’t know if that changes anything as far as shutter.

2. If I slow it down to 50 percent, then I should shoot with a shutter of 480?

3. It shoots 120fps in 2.5k. In 4k, I believe I can shoot 60 frames per second with less compression. Am I better off shooting less frames per second with a higher quality file or more frames per second with a lower quality file?
 
More frames are better for slow-motion software. Ideally you'd want more frames and less compression, but if that's the choice you have then more frames would be better.

Use the highest shutter you can.
 
1. No, I don't think the 24fps timebase changes anything as far as shutter is concerned

2. Right, slowing down to 50% yields an equivalent 240fps, so 1/480 would be 180-degree equivalent shutter. I don't think there's any harm to going even faster and there may be a benefit. But if memory serves me, 1/480 should be enough.

3. The best way to decide this question is to run a test each way and compare. I couldn't say for sure. My guess is you're better off shooting 120fps in 2.5k as you'll have more real frames and fewer interpolated frames. But maybe it depends on how much you slow it down. If you're going to interpolate a lot of frames either way, maybe the higher resolution is better? But generally of course you want as high a framerate as possible
 
Looking online now, the general recommendation is shutter speeds of 1/2000-1/4000. Can't remember where I read 180-degree equivalent.

And use lower res, higher framerate as long as the resolution is adequate (like 720p or above)
 
The optical flow in FCP X is awesome with the right content. You'll see the traditional warping when things cross/blend, but I mean...what does one expect, you know? Especially for what I imagine is just a passion project for YouTube.

If you don't want to pay for software specializing in it (which isn't perfect either), you'll have to obtain a high-speed camera for best results.

One of my favorite slow-motion dunks...starts at 2:13:

https://youtu.be/n-vb1kBDoD4?t=133
 
You wouldn't be laughing if you saw some of the bank accounts of the people with Phantoms who have food and sports contracts with these national brands, ha.
 
So I shot a bunch of footage. I am going to post my results soon to see how good or bad optical flow slow motion can be. Just wanted to run by some math with you...

If I shot 120 fps, then to make it real time in premiere pro, I would have to speed it up to 500%?
If I slow it down 50 percent, it's equivalent to 240 fps?
If I slow it down 25 percent , it's equivalent to 480 fps?
If I slow it down to 12.5 percent, it's equivalent to 960 fps?


I shot everything in 2.8k raw. I got my shutter as high as 1920. I tried to get a low ISO, but usually between 800-1000 (needed lots of light for that shutter speed). I am going to slow everything using optical flow to see if any of it is useable. To help it, I used a tripod and tried to keep the backgrounds simple (although not always).
 
That math sounds right (for a 24fps sequence)

Yes you need a lot of light when working with such a fast shutter
 
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