Newbie Question-24P and 24Pa

[Marc Butcavage]

Hello,

I'm a new member to the forum and I have had my XL2 for about a year and a half now. Unfortuantely, I'm stuck editing on iMovie, but I'm in High School, so I guess that's normal at least for the time being. I jsut had a question about 24p and 24Pa. What is the difference? If anyone can just give me a quick overview of both that would be great. I've read some past posts, but I am lost in the editing world with anything beyond freeware.


Thanks again,

Marc

[Chris Hurd]

Transferring your project to 35mm motion picture film? Use 24Pa (known as 2:3:3:2 in the XL2).

Not transferring your project to 35mm motion picture film? Use 24P (known as 2:3 in the XL2).

That's the gist of it and pretty much all you need to know in very simplistic terms.

[Eric Shepherd]

Originally Posted by Chris Hurd

Transferring your project to 35mm motion picture film? Use 24Pa (known as 2:3:3:2 in the XL2).

Not transferring your project to 35mm motion picture film? Use 24P (known as 2:3 in the XL2).

That's the gist of it and pretty much all you need to know in very simplistic terms.

What if you don't know if your project is going to film? I've been shooting a film (er, 'movie') for about 4 months in 24P, but we don't know if it'll get picked up for festivals, etc. Would this cause any problems? And would switching to 24Pa at some point during shooting cause larger problems or a visible difference? I've captured all footage to date in 24P 16:9, so the files are all 23.976.

Thanks Chris :)
-Eric

[Jack Barker]

Originally Posted by Eric Shepherd

What if you don't know if your project is going to film? I've been shooting a film (er, 'movie') for about 4 months in 24P, but we don't know if it'll get picked up for festivals, etc.

I think most festivals today use DVD projectors, so you should be all right. The cost of printing to 35mm is hideous, and well beyond the reach most independent filmmakers.

[Eric Shepherd]

Originally Posted by Jack Barker

I think most festivals today use DVD projectors, so you should be all right. The cost of printing to 35mm is hideous, and well beyond the reach most independent filmmakers.

Ah alright, thanks. :)

And is there a visible difference between 24P and 24Pa? Are there fewer interlaced frames with Pa?

[Jack Barker]

Originally Posted by Eric Shepherd

Are there fewer interlaced frames with Pa?

Read this on Adam Wilt's site:
http://www.adamwilt.com/24p/index.html#24pRecording

[Eric Shepherd]

Originally Posted by Jack Barker

Read this on Adam Wilt's site:
http://www.adamwilt.com/24p/index.html#24pRecording

Thanks for the link. I don't understand this part though:
"Shoot 24p Standard for:

* Getting the “film look” on video when you're staying on video and editing at 29.97.
* Intercutting with film transfers also using 3:2 pulldown, and staying on video at 29.97."

I realize that 24P is stored at 29.97, but isn't there redundant info in there? Isn't capturing to 23.976 better because it uses less space and has all the same info? It seems every time I read about this stuff, I find contradicting info. :)

Thanks!
Eric

[Michael Jouravlev]

Originally Posted by Eric Shepherd

Ш realize that 24P is stored at 29.97, but isn't there redundant info in there? Isn't capturing to 23.976 better because it uses less space and has all the same info?

Because video is recorded in the format compatible with broadcast standards.

[Eric Shepherd]

Originally Posted by Michael Jouravlev

Because video is recorded in the format compatible with broadcast standards.

Yes, but DVD's are also done at 23.976. So I'm wondering which way is 'proper' for a direct to dvd short film? It's all shot in 24P and most of the things I've read say capture as 24fps, rather than 30fps..

But then this one says do 30, so which way is right?

[Jack Barker]

Here's another article link from Digital Content Producer - "Shooting for DVD"

http://digitalcontentproducer.com/vi...DVD/index.html

[Michael Jouravlev]

Originally Posted by Eric Shepherd

Yes, but DVD's are also done at 23.976. So I'm wondering which way is 'proper' for a direct to dvd short film? It's all shot in 24P and most of the things I've read say capture as 24fps, rather than 30fps..

But then this one says do 30, so which way is right?

What do you mean "direct to DVD"? Do you mean that your camera writes to DVD, not to tape or hard drive or flash media? This is an interesting question, I wonder if there exists a DVD-based camcorder that writes directly as 24p. That would make sense.

Who says "do 30"? You did not provide the reference... Anyway, if you are writing to tape first, it is 24fps, but within 60i stream. This way you can watch video directly from the camera on a consumer equipment, even on a old-style analog CRT TV. Also, you can edit video as if it is regular 60i.

I don't think that you can shoot true 24p with regular DV or HDV. After all these standards were envisioned as consumer standards. So the only way to get 24p from these systems is to store it in 60i stream. Once you are mastering a DVD you can create a true 24p DVD by reverse telecining if you want. Obviously, your software has to support that.

[Eric Shepherd]

Thanks for the link Jack, I'll check it out.

Mike, direct to dvd, as in not going to theaters first. I have an XL2 after all, so it's standard DV codec all the way for me. :)

I can't find anything at the moment about capturing to 24fps vs 30fps timelines. But I've seen posts about resources and cpu efficiency capturing at 24fps.

I use Premiere Pro or Vegas, depending on the project.

[Joseph Andolina]

I was doing some test shooting for a upcoming PSA I need to work on. Was seeng what the differance was between 24pn & 24pa in post with FCP5. There is one shot that we will be needing to make it look like it was shot with a fisheye adaptor (we won't have one). And the thing I notice is that after doing that to the shot on the timeline, with 24pn, there is very noticeable aliasing going on, with 24pa, it is very slight. So we were going to choose shooting in 24pa. The final project will be going directly to DVD. Doesn't it output to DVD as 29.97? Or would there be any problems with the frames playing?

[Eric Shepherd]

Originally Posted by Joseph Andolina

I was doing some test shooting for a upcoming PSA I need to work on. Was seeng what the differance was between 24pn & 24pa in post with FCP5. There is one shot that we will be needing to make it look like it was shot with a fisheye adaptor (we won't have one). And the thing I notice is that after doing that to the shot on the timeline, with 24pn, there is very noticeable aliasing going on, with 24pa, it is very slight. So we were going to choose shooting in 24pa. The final project will be going directly to DVD. Doesn't it output to DVD as 29.97? Or would there be any problems with the frames playing?

You can do the DVD as 29.97 or 23.976fps. That's kinda what I was getting at with my question too. From what I understand, 24P is storing a few extra frames, but isn't actually 29.97 frames worth of data. So capturing at 23.976 will save drive space and rendering time. Then you can output to a 24fps DVD (I believe either interlaced or progressive?), and then the player will spit out 29.97fps to the display device. The final result is you save space and power editing and you can fit 20% more on the DVD and get the same playback performance.

I've noticed vertical bands in my footage sometimes. Almost like every 100 pixels or so, there's a stretch of 10 pixels. It seems more apparent on strong blue images. I'm shooting with a Soft/FX 3 filter, but that has an obvious pattern that looks nothing like this. It's almost like it's shooting narrower than 720px and stretching at a standard interval. Anyone else getting this?

Eric