24p in fast motion

[Guest]

Hi. I've been editing this video for a little while now, and it was all shot in 24p mode on my DVX. There's one shot that I have where I just filmed cars going by in the street and then I sped it up a bunch. I didn't notice anything wrong with it on my computer screen.

I hooked up a monitor to my computer so I could get a nice look at what I was doing, and I realized that the sped up clip of the cars looked home video-ish. The reason, I think, is because when you speed up a clip that was shot in 24p, the squeeze thing that Panasonic invented (the one to fit 24 fps footage onto a 30fps tape) is undone or something.

So what happens when I'm viewing the video on an NTSC monitor is everything will be all nice looking, and then comes this clip that looks like 30 fps...because it truly is. Is there a way to convert this clip to 24 fps or something? I don't want to have to worry about this one shot being the oddball in my video, and I can't take it out.

Any ideas and help will be greatly appreciated. Thanks in advance.

Gabriel Gall

 

[dashwood]

Re: 24p in fast motion

First off.. are you editing in a 23.98 sequence, or 29.97 sequence?

If you are working in 23.98, FCP will attempt to interpolate any speed ramps you do to still end up being 23.98 P. This therefore won't give you the "video frame rate look" associated with interlaced 29.97.

However, I suspect that you shot normal 24P on the DVX, digitized as 29.97 and are working in 29.97. What you should do is export the clip you want to speed up as a quicktime file, remove the pulldown (reverse telecine) of your original footage in cinema tools, and then re-import the new 23.98P file back into FCP.
Now create a new blank sequence at 23.98 DV, and edit the new clip into it. Perform the speed up in the new sequence.

Now you can edit/nest the new SEQUENCE into your 29.97 timeline, and FCP will add the appropriate pulldown for you. (Will require some rendering.) The nice thing is that the speed calculations were performed in a 23.98 progressive timeline, so your 29.97 timeline just sees the nested & rendered 23.98 footage, and doesn't care that it was sped up.

For best results use even speed percentages like 200%, 400%, etc., and turn off frame blending. Only use frame blending for odd percentages, or slowing down shots.

In the future, if you shoot 24P advanced, you can remove the pulldown during digitization (requires FCP4), and then cut in 23.98P sequences, but still output standard NTSC when you are done. No worries then.

Tim

 

[Guest]

Re: 24p in fast motion

Wow, that was a very detailed answer ;D

Only problem is, I'm using FCP3 and and I don't have CinemaTools. I'm a 15 year old kid with no money...

Does this mean there's nothing I can do at the moment?

Thank you much for the nice reply.

 

[dashwood]

Re: 24p in fast motion

Do you have after effects? You can remove the pulldown in AE.

If you don't have AE, you can still make a new DV NTSC sequence in FCP3, set the frame rate to 23.98, put your 29.97 DVX clip into it, do the speed change, and then edit/nest the new sequence into your cut. The nesting feature didn't really change from v3 to v4.