24P or Slammed Saga Continues

Looks like the interlacing every 4 frames is probably a "3:2 pulldown" problem.  Apparently, when you shoot in 24p, you can't avoid interpolation (3:2 pulldown).  Basically, your program adds made-up frames to your footage. I thought that because I started from scratch by loading the 24p footage into my editing program in 24 mode, that it would go from native 24 in the camera to 24 in Premier and there would be no interpolation.  But what happens is that to display it on just about anything other than in a traditional theatre, the footage needs to be converted.  For the computer screen, it's from 24 to 30 frames/sec.  Even if I put it on a DVD and show it on a TV, it still needs to be converted. 

The bottom line is that it's a pain to process 24 frames/sec.  Filmmakers do it because it supposedly looks more film-like while 30 fps looks more like video.  Basically, you're reducing the quality of your video to make it look more like the old technology the audience is used to seeing in theatres.  TV typically uses 30 fps so the audience is used to associating it with TV shows.  Also, if you're ever going to film out and convert your video to film, 24p will match the rate of film.  I went out of my way to get cameras that shoot in 24p... but despite what the experts say, I'm beginning to have doubts about the format.  Maybe a little experimentation is in order...

Anyway, still trying to figure out what to do about the interlacing problem.  It goes all the way back to my original capture in Premier but not for the entire capture, only sections of it.  I may need to recapture and do those sections over again... the real bummer is that I rotoscoped some of those sections (not realizing what I was seeing and chalking it up to Premier's on-the-fly rendering which they warn you about)... so many hours wasted on 24p.

If anyone has advice on this, let me know.

Susan Ee
http://feraldream.com

Tags:
This also appears in:

Next Posts

Previous Posts

Comments

Shaun Huston
I spent a good part of yesterday obsessing about 30p v. 24p as I am about to begin shooting on a feature-length documentary project and need to make the choice. Technically, I have a Panasonic DVX100a and will be editing in Final Cut Pro. If I mind what I'm doing, my understanding is that I should be able to edit in a "true" 24fps timeline, but the truth is I've become comfortable with 30p and it does simplify both shooting and editing. The differences are noticeable, but often subtle, and probably primarily to those who spend a lot of time thinking and looking at such things. The reason I'm leaning towards 24p is to keep open the possibility of transfer to film. From what I've been able to gather, shooting in 30p pretty well precludes distribution on film. However, in a fully digital world, I'd probably shoot in 30p without giving it much of a second thought. Complicating things is the fact that I'm currently thinking of using time-lapse footage, which I can't shoot in 24p, only 30p or 60i. 60i is easier to translate into film, but it will probably look like the local news.
Susan Ee
I don't make documentaries but I wouldn't hesitate to use 30p for a doc. There really isn't a suspension of disbelief issue with documentaries the way there is in narratives. We take in a bunch of cues that translate to "Once upon a time..." and the flickering of 24p may be one of them. Even despite that, I'm considering going over to 30p to simplify life. I've taken it on faith that you can see the difference because I can't see it on my computer (which converts to 30 to display) nor on a DVD. I can see that there's a difference in movies vs. TV but I'm not sure that's the 24p at play rather than the extra $100M spent on production. The jury's still out for me.

Won't you be able to film out from 30p by converting digitally from 30 to 24 fps before you convert to film? Does that make it jerky or something?

Also, there are about 200 digital theatres in the US that should be able to play 30p so that's one option. Let us know what you decide and how that all goes.

Congrats on starting a documentary, Shaun!
Susan Ee
BTW, I'm a little fuzzy on this but my impression is that for cameras that record 24p onto tape, like the DVX100, it processes the image in 24p but it records it on tape in something else (30 or 60) and if you're lucky, it flags the extra frames (this is a real problem for the Canon HV20 which either doesn't put in the flags or the NLEs can't read them). When your NLE (either Final Cut or Premier) captures it in "true 24p," it's taking those extra frames out. You edit in 24p but you can only see it in 30 because it needs to be displayed to you while you're editing so it'll convert again. Or I guess it's possible that the NLE doesn't take out those extra frames from the tape since it has to put them back in to display it to you anyway but my guess is it strips it, then puts it back in during display. The end result is a lot more on-the-fly processing than if you had shot in 30p to begin with. I think my interlacing problem is probably from one of these conversions messing up. I just need to figure out how to fix it.
Shaun Huston
I'll be the first one to admit that I don't fully understand the technical details behind all of the ramifications of these choices. For whatever reason, it seems pretty universal that 30p to film just does not work, to the point where very few, if any, shops will do it. As best as I can figure from the various forum discussions and faq lists, etc. that I've perused, it has to do with not having enough information to "lose" in the conversion without producing, especially, motion artifacts (60i is, evidently, much easier to convert because it provides more "head room," but generally won't look like much like film regardless).

The look and feel issue is one that comes up frequently in these discussions, and you are right that part of the attraction of 24p for scripted works is its more "dreamlike" quality, which may or may not be necessary for a documentary. The spread of digital projection, and the option to submit screening copies to festivals on dvd or mini-DV does make 30p highly viable, but it's hard not to think about "proper" theatrical distribution, which still means film.

As I think through these issues more, I think I might play around with 60i in different gamma settings, shutter speeds, etc. to see what I can get in terms of a look that doesn't automatically remind people of soap operas or the local news. As you note, with a doc I can get people to accept a more "immediate" feeling image than if I were doing a narrative feature. But I would like to avoid the cold, electronic look that signifies "video."

(I think your description of the editing process is more or less correct; 30p/60i is definitely easier for that reason, not to mention requiring less care with the camera, which is something else I need to think about as I will likely have multiple operators with varying skill sets).

Post a comment

Already a Vox member? Sign in

You will be asked to join Vox to post this comment.