720@60fps> CT to 23.98> FCP clipspeed to realtime = ?

[Christopher Drews]

Here's my perceived workflow:

7D shot 720@60.
Cinema Tools to 23.98.
FCP speed to real-time without frame blending.
My question is, what's the math? How fast would I have to speed up the clip to real-time?
Will this look weird?
Is FCP dropping frames to make this happen?

Hypothetically, you could shoot an entire narrative at this frame-rate and have slow-motion for any given shot. You'd decide that part in post.
Does this seem feasible?

Thanks!
-C

[David Chapman]

Hey Christopher,

The math is like this:

60/24 = 2.5
24 conformed will have to be sped up 250% to get back to the 60p rate.

59.97/23.976 = 2.50125
23.976 conformed will have to be sped up 250.125% to get back to the rate.

I don't know if the decimal value will work better than just the 250%. I might try this later on since I shot some 60p today.

Hypothetically, you could shoot an entire narrative at this frame-rate and have slow-motion for any given shot. You'd decide that part in post.
Does this seem feasible?

Yes, I think you can. It might be easier to set your normal rate (speed up back to original 60p) and then slow down in some areas. I see a lot of keyframes.

I'm actually looking into shooting everything at 60p and then using Compressor or MPEG Streamclip to transcode to ProRes and 720p24 at the same time. There is little skew in 60p compared to 1080p24, and I don't need to have 1080 just to have it.

[Christopher Drews]

Sorry, David - I wasn't clear to begin with.

I'd like to re-time the clip to real-time playback after CT processed to 23.98.

In other words, maintain real-time by editing in a 23.98 sequence.
If the clip would be slow motion, I'd just have to remove the speed effect check box in FCP and re-render.

Was curious if the math lines up and if this is even a plausible workflow.

Many new cameras aside from the 7D, 1D and soon the 5D are allowing for 720@60fps - so adding slow motion to your tool box is great, if you have the option of going back to real-time while maintaining 23.98, because who really wants to edit in 60fps.


OH - you just edited your post - That's what I was looking for!!
-C

[David Chapman]

[updated]

Are you looking to shoot all 60p just for the times you may need to slow it down in post? It's pretty easy (with the Q button) to toggle back and forth between the 24p and the 60p, but it will be a little bit of a hassle in post.

Your question then becomes, do you conform all 60p to 23.976 and then retime (speed up) every clip in FCP as you edit? Or do you transcode to 23.976 on all your clips before you edit, changing your 60p to 24p and then only conform certain shots to 23.976 that you want to variable speed change inside FCP.

Does that make sense? I think we are in new territory here. Where the heck is Tim Dashwood?

[Christopher Drews]

David,
Yes, I heard about the skew being lesser at 720p.
I'd love to see a sample once you get it processed.
Thanks again,
-C

[David Chapman]

Shooting 60p all the time.

I'm doing some tests to discover other pro's/con's in shooting everything 60p and then transcoding to 23.976 with MPEG Streamclip in post.

Pro's
Less skew on pans
Ability to have 2.5x slower shots on anything.
Transcode time not significantly increased from normal ProRes recompression.

Con's
Increased moire and aliasing (said by some in 60p mode)?
Preview and playback will be 60p until capture and converting and look like 60i material.
May not have the "film look" or actual 24p?

The issues above may be non-issues. I will know later.