Speed Ramping / 300 / HVX / Variable Frame Rates

M

machardi

Well-known member
The Situation: I need to emulate the speed re-mapping of the movie '300', but am a little stumped on how best to use my tools (AE, and an HVX) to do it.

I know that the HVX has variable frame rate shooting (but I don't really know how to take advantage of it) and I know that AE has Time Remapping as a function.

All of the tutorials for doing time remapping are based on cameras that don't do VFR, so I wonder if the HVX offers me options to make it look better that those tuts neglect, through no fault of their own.

Should I shoot in an overcranked speed, and slow it down, or good ol 60i? Or what? I am a bit confused.

Any advice would be greatly appreciated,

Thanks,
Phil
 
You can shoot 60 and then drop it in a 24fps timeline, but I prefer shooting overcranked in 24PN and then dropping it in, because you can see it in the camera after shooting. If you shoot it in slow-mo, it'll look better slowed down and you can speed it up simply by cutting out frames.

If you need the sound alongside, though, then shoot at 720p60 and you'll still have sound.
 
Thanks for the quick reply,. When you say 'simply by cutting out frames' do you mean manually deleting ever [x]th frame? That sounds a bit difficult.


Phil
 
I would agree to shoot at 60fps to get as many frames as possible, when slowing you footage down it will look best that way.

Time-remapping in AE will do the math for you for taking out the extra frame to play the clip in real-time once you set accordingly. If you slow down the shot to a slower framerate than you shot, make sure frame blending is turned on.

I haven't done it with HVX footage yet, but, shooting as many frames as possible and making multiple keyframes with time-remaping in AE should give you very good results.
 
You don't need to manually delete frames, but if in FCP you want to up the speed of a shot, you can say set it to 200% and FCP will cut out every other frame and speed up the audio to match (if you're using audio). This works great for speeding up clips because you toss out what you don't need.

But you want to slow things down, you need more frames or else your program has to make them up by guesstimating what's inbetween frames. If you want something to play at 50% speed, you need to roughly double the amount of frames you have in that clip. Which is why it's better to shoot extra frames to begin with, and delete them to speed up in post.

I've shot birds in flight (and fighting) in slow motion and, slowed down even more, it's held up with great quality. When you film at regular speed and then try to slow down, you can get ghosting.
 
First, don't shoot 60i! Shoot 720/60p. You can't execute speed ramping in-camera, you have to do it in post, but start with progressive footage and you'll get much better results.
 
Thanks everyone I will take your advice to heart and see what I can come up with. I am grateful to you for taking the time to advise me, very gracious of you.
 
As barry said, definitely shoot at 720/60p, but instead of using AE or FCP/Premiere slo mo, get your hands on a plugin called Twixtor.

It will get you glassy slow motion effects with no ugly frame blending artifacts down way lower than 4:1. It also allows for ramping.

Twixtor works on the tracking pixel motion and creating whole new frames and is amazingly accurate when given a sharp image, so make sure you shoot with a high shutter speed and there is no motion blur on the shots you want to apply it to. You can grab a demo of twixtor here...

http://www.revisionfx.com/products/twixtor/
Hope this helps. . .
 
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