24p motion and shutter speeds....

[MattC]

Ok, so I've read through all the threads regarding strobing and camera movement and shutterspeeds. But I'm still not getting the hang of this 24p thing. I understand it in theory, but in practice it just doesn't look, motion wise, like I think it should when viewed in my NLE. I just finished shooting some test footage (nothing great, I'm cooking an omlette) and have the camera set to 24p advanced and shot at shutter speeds of 24, 48 and 60. So far the 1/24 seems the smoothest even though there is blur. FWIW, I did not move the camera at all, they are static shots the only thing moving is me. I also shot some footage (1/48 only) of my washing dishes. The 1/48 seems a little jerky to me, even though the camera is not moving. I'll try to post samples later tonight, but in the meantime, is this common? What I mean is, are there common mistakes that I'm likely to be making?

Thanks,

Matt

[mgalvan]

Hi MattC,

The thing with 24p advanced is you have to realize that it is using a certain pulldown cadence (2:3:3:2) to convert the 23.98fps to 29.97fps to conform to NTSC standards. If you were to just look at this tape in the raw, it would probably seem a little jumpy because of this pulldown pattern (and maybe bacause you aren't used to seeing any 24p footage also). This shooting mode will look this way because this pulldown method was actually created to allow you to extract the true 24fps that the camera shoots. If you were to take your footage into your NLE and rmove the advanced pulldown, you will then get your true 24fps.

Try your test shoots again in regular 24p (not advanced) as it uses the standard 3:2 pulldwon method to tape. This will give you a better idea of how 24p footage would look on an interlaced monitor. Ok, gotta go ... got a shoot a host for the next hour ...

[Neil Rowe]

24pa is not designed to have smooth motion .. its designed for getting the pure 24p back out of it.. its not intended to be the final delivery method.. you should shoot in 24pn if you want smooth film like motion right out of the camera, and dont need to work with true 24p. 24pn uses a cadance thats the standard, and the smoothest playback for 24p on an NTSC system.. and is whats used when regular films go to video.

24pa takes the 24p from the camera, and arranges it so you can get it back out of the ntsc stream without recompression in the native DV format. ..then you can edit and output true 24p for web-filmout-or whatever. ..if you want to sho it as NTSC video.. you would output the 24p with the 24pn cadance for smooth playback.. just like the 24pn you get straight out of the camera if you shot in 24pn.

[MattC]

Ah, the grasshopper is learning...

So master let me ask you, I see most of the folks here are shooting 24pa and recommend that setting. Is if because the all intend to do a film out? (I would find that hard to believe).

Matt

[scharky]

What NLE are you using. *24pa isn't just for a film out, you can use it anytime you plan to edit in a 24p timeline (DVD output or computer output). *If you are using a program like vegas that automatically detects the pulldown, just set your preferences of you timeline to DV NTSC 24p and it will automatically play just the 24frames that it is supposed to.

[Neil Rowe]

most people shoot 24pa and edit as true 24p because they have a 24p master that they can *output as true 24p for : film - 24p DVD- web- computer video-.. and if they want they can telecine it with the 24pn cadance and output for NTSC playback. * *

if you start with 24pn, and stay in native DV editing, you get the smoothest motion, but you have to recompress the footage 1x to reconstruct the original 24p from it. so you lose a little quality to do the same thing.. (thats why 24pa was developed..to get around the generation loss from recompression.. but agin its not supposed to be used as your output format) so most peole only use 24pn if they are sure they are not going to use true 24p for anything, but still want the film type motion and want to work with 24p telecined to NTSC 29.976 right from the camera.

if you wanted progressive without film type motion at all you would use 30p.

[Barry_Green]

Let me take a wild guess -- you're using FCP, aren't you?

Man, there's something wrong with FCP's handling of 24P. I'd say *all* the complaints I read about on the various boards about editing and 24P are coming from FCP users. Yet some people swear by it. I can only guess there's some vagueness in the instructions. I think Noah Kadner offered a 24P FCP tutorial over on 2-pop just to try to clean up the questions.

All I can say is, trust us, 24P and 24PA can be edited identically and deliver equally smooth motion (or, equally stroby motion, depending on how you want to look at it).

[MattC]

YES, I AM ON FCP!!! *(the bastards)! *;) *T be honest, I love the program and it's workflow, this is the first time I've run into any issue at all. *Just to be clear, I bring the video in and it is brought in fine and (I think) plays fine, just a hair jerky. *I need to post a clip...

So still not sure which "24" to use if I'm making, say a short film that will only be seen on the web or on dvd - but it seems that if I have the ability 24pa would offer more options although 24p would be a tad smoother. *Correct? *Also, for really high quality cinematic adult entertainment, what would you recommend I shoot that in? *::)

Edit: Barry, I'm going to be in Sin City at the end of the month. You up for a beer?

[Antoine_Fabi]

I use Final Cut Pro HD and it works perfect with 24p and 24p advance.

...perfectly !

[Barry_Green]

YES, I AM ON FCP!!! *(the bastards)! *;) *T be honest, I love the program and it's workflow, this is the first time I've run into any issue at all. *
I'm sure it's not a problem with FCP, I think it's a problem in the documentation. *Too many people are complaining about problems with it, yet guys like Noah Kadner swear by it, so I've got to assume that somehow there's some step that's not adequately documented. *Someone who's an FCP guru needs to post a step-by-step tutorial on working with 24PA in FCP, so you FCP users can sidestep this apparently-common frustration.



So still not sure which "24" to use if I'm making, say a short film that will only be seen on the web or on dvd
24PA, no question. *But only if edited on a 24P timeline.


although 24p would be a tad smoother. *Correct?
No -- when edited on a 24P timeline, they are equally smooth. *The only "smoothness" difference would be observed if playing directly from tape and editing in a 60i timeline.

If editing in a 24P timeline, always always always use 24PA. *If editing in a 60i timeline, use 24PN. *Although either mode can be used in either, they're best used in those circumstances.


Edit: Barry, I'm going to be in Sin City at the end of the month. *You up for a beer?
The end of this month? *Almost no chance -- I'm working solid from the 24th through Feb 3. *But hey, write a PM when you're in town and let's see if we can do something, I don't know the hours on the convention shoot yet, I may get off at a reasonable hour...

[MattC]

I finally got the tech issues resolved. I'll write something up and post it. You're not shooting the SHOT show by any chance are you? Did I mention I'm buying the beer? (You're on your own for the girls, however.)

[Barry_Green]

Yes, the SHOT show... don't know anything about it though...

[MattC]

Well, I'm going to be there. *

My partner has a booth there Snipers Hide booth 830 in the Law Enforcement Section (he's a former marine sniper and runs the largest website for tactical shooters in the world www.snipershide.com)

He'll be at the show the whole time, I on the other hand will be visiting with my parents, shooting dice, drinking and carousing with the wrong sort of women. *Are you shooting for their SHOT tv? *By the way, the dates of the show are the 28th through the 31st. *

Matt

EDIT: It is the largest shooting, hunting and outdoors show in the country. Lot's of guns...

[Barry_Green]

Ah. So when I say I'm "shooting" the shot show, one has to be careful with their terminology, right? :o

Well, I guess I may run into you after all!

As for the client, it's for shotshow.tv. As I understand it it'll be a relatively live-ish broadcast from the show floor. We're starting on the 26th with load-in and lighting the set, then the 27-31 shooting interviews/booths/etc through the 31.

[MattC]

Hey Antoine, what compressor setting do you use to compress the file. If I use the setting for 24p source material, the footage gets "squeezed" (almost like panavision) I'm shooting the XL2 in 16:9 to begin with. However, if I export as a regular NTSC mp4 then it renders smoothly and exports as a 4:3 file with the black matte bars on the top and bottom and the aspect ratio is correct. Can't seem to get it so that there are no black bars and it displays the correct 16:9 aspect ratio. And yes, I am editing on a true 24p timeline. I did not have this problem when editing a 24p (not advanced) on a regular NTSC 29.976 timeline...

Matt

[Antoine_Fabi]

Hi Matt,

I first capture the footage as if it were normal 29.97 4:3 timebase.
I always capture the entire footage, not only the chosen scenes.
Then i remove the pulldown (Tools menu)
I set my timeline setting as follows:
* * * Editing Timebase = 23.98
* * * Anamorphic (if i used the anamorphic adaptor or squeeze mode)
(Should be the same if you shoot 16:9 with the XL2)

I then select the captured clip and go in the Edit tab and select
"item properties" and check "anamorphic"

Then i make subclips to work in the timeline.

At this stage, if your monitor is not 16:9, it is normal that you see
footage (full 4:3) as squeezed.

I then export the finished product as a self contained FCP file.

I use "Compressor" for MPEG2 output.
My settings are:

Encoder tab: video format 24p
* * * * * * * * *Aspect Ratio 16:9
Quality tab: *Mode: Two pass VBR Best
* * * * * * * * *Average bitrate 7 Mbps
* * * * * * * * *Maximum Bit Rate 8.5 Mbps
* * * * * * * * *Motion Estimation = Better (looks better than "best")
GOP tab: * * *GOP structure IBBP Open
* * * * * * * * *GOP Size = 6

It will display 16:9 letterbox automatically on a DVD player pluged on a 4:3 monitor, and it will also display 16:9 correctly on a DVD player pluged in a true 16:9 TV monitor.

Works great.

NOW...
If you want to go to VHS or 4:3 for broadcast, just create a new 23.98 timeline, select your final product file and make sure "anamorphic" is checked in the edit/item properties menu (it should, if not, select it).

Drag your final product in the non anamorphic timeline, and it will display letterbox on a 4:3 monitor. (For VHS and normal 4:3 Broadcasting)

Good luck
(sorry for my bad english...)
Let me know if it works OK for you.

Antoine

[bkgauthier]

I am interested in converting 24p standard footage to 24pA so that I can use it on a 24p timeline with other 24pA material. I could just use the 24pA footage on a 29.97 timeline with the 24p standard footage (the 24pA footage is interview talking heads, so there's not a lot of movement in the frame), but I'd like to be able to output to a 24p DVD so I'd prefer converting the other way around. Also, my hope is to minimize interlacing artifacts as much as possible. I have found solutions for converting the 24pA to 24pN with Graeme Nattress' conversion tools, but I have not found the details for how to convert 24pN (SD) to 24pA in Compressor. Any word on this issue?

I've heard that cinema tools can sometimes accomplish this, but not ideally because it does not read the changes in cadence that happen with different clips on the same tape. I understand that it is ideal to do it in Compressor if you get the custom settings right and that Compressor will actually read the changes in cadence and change the pulldown pattern accordingly and more continuously than Cinema Tools. Does anyone know how to create this custom filter in Compressor and what the right settings are? I have only used Compressor to compress files to mpeg2, h264, 10bit, etc. I'm not familiar with Cinema Tools much at all.