2012 August 10th, 15:06
Speed ramping under 24fps back to 24fps - help!
This is more of a frames per second question than anything else.
So I could be using a Canon 5dmII with the Magic Lantern hack, or a Sony FS100 where the frame rates can be selected manually. At the end of the day, the file on the card shows the footage as being shot in a 23.976 capture. You with me?
Now, lets say for instance I shot a sequence at 3fps. The way the footage comes off the card is like this:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 -FRAMES
A A A A A AA B B B B B B B B B C C C C C C C C -IMAGES ON FRAME
So even though I'm shooting at 3fps, I'm actually getting 24 frames with many of the frames repeated to get me down to 3fps. Still tracking?
My question is how do you go about REMOVING the repeated frames so the footage can be remapped to an actual 23.976 time line.
Obviously, if I'm shooting at 3fps and I do this the footage will be very much sped up, but of course, if you're doing a dangerous stunt (like a car driving by a person's hand in the film Brick) you don't want the mustang driving past at 40mph, you film it slower and then speed it up. I have no idea how to do this when the footage is stored in a 24fps wrapper of sorts.
The same (and more relevant to everyday shooting) question is for filming at 22fps to then speed up to 24 for fight scenes, which is one of the many reasons to get magic lantern.
2012 August 11th, 03:25
So you would shrink the footage by a factor of 0.91758 to make 22fps look like 23.976 fps. Just make sure you tell the actors to act 0.918 their normal speed!
Regarding the other question, you Would simply disable the programs interpolation, in vegas youd hit disable smart render. Then you would speed it up by 8 to get it looking like 24p. But make sure the driver was going 1/8 the desired speed.