First time shooting 24P

[valrio]

I just got this camcorder - DVX100A and I will admit I'm totally overwhelmed. I've only had it one day and have been tinkering with the settings for almost 15 straight hours. I'm somewhat familiar with what it does - but how to do it and how to render it - I'm Mr. Stupid. I shot some video in 24P and it looks "jerky" as well as a lot of quality loss. So what should the settings be for shooting in simple 24P or should I shoot 24AP? Another question - what to do after I download it into Vegas Video - edit it and then .....RENDERING! There are so many choices. I don't know how many out there use Vegas Video 5.0 but I think it's a great program and easy to use but what to do after I'm through with the editing is driving me crazy. I've know how to render basic full screen no frills video and it looks passable. But I want more since I spent almost $5000 and want my money's worth. (I had a cheapie Sony TRV38 and was not happy with the quality) Any help would be greatly appreciated.

[David Mullen ASC]

There shouldn't be any quality loss by using the camera in progressive-scan mode.

 

24P should be jerkier than normal 60i capture. You are only sampling motion 24 times a second rather than 60 times a second. 24 fps film is jerky too; that's why you have to be careful how fast you pan sometimes. Make sure you don't have the shutter set to something quicker than 1/48th to 1/60th of a second because it will make the jerky motion issue worse.

 

I've also found that the jerkiness looks worse on the camera's LCD screen than it does later on a normal TV set.

 

24P Advanced is used for only one reason: to make it easier to remove the 3:2 pulldown when importing the footage, assuming your software supports 24PAdv. pulldown removal. In other words, you use 24PAdv. when you plan on cutting in true 24P instead of normal NTSC 60i. Some software will remove the normal 3:2 pulldown used by regular 24P mode, but I think the point of 24PAdv. is that it's faster to remove the pulldown because software like in FCP will remove it while it imports the footage (I'm not an editor so don't hold me to this.)

 

You can just leave the pulldown in and cut it like normal 60i footage if you only plan on showing it on an NTSC TV set, although it can be nice to store it on DVD as true 24P (takes up less space and I suppose some progressive-scan displays will handle it better.)

[valrio]

Thanks for the explanation. I think I understood what you're saying but I have another question about "pulldown"....what is that? I know there are diagrams explaining it about the fields and I understand the 2:3 and 2:3:3:2 but you mentioned "removal?" Why or how should it be removed? I think Vegas can edit in 24P. I need the final product to be on DVD and viewed on a progressive scan DVD player.

[David Mullen ASC]

NTSC television is 60 fields per second (60i). Film is 24 frames per second. There are two fields per frame of video; each field contains the alternate sets of lines needed to build a complete frame of video. The NTSC version of the DVX100 can only record in 60i; this allows the recording to be viewed on any NTSC monitor.

 

Well, if you merely split each frame of 24 fps film (or 24P video capture) into two fields, you'd end up with 48 fields, not 60. So you have to repeat certain fields to make up the difference. That pattern of repeated fields is called the 3:2 pulldown.

 

Basically, there are five video frames created for every film frame to convert 24 frames into 30 frames / 60 fields. The first film frame is represented by two fields, but the next film frame is represented by three fields. This means that the third video frame will be made up of one field from the previous film frame and a second field that comes from the next film frame.

 

So the 24 progressive-scan frames you captured per second are being stored on tape as 60 fields. With standard 24P mode, you use the standard 3:2 pulldown I described above. Some software can remove that pulldown and leave you back with just the original 24 whole progressive-scan frames (sometimes this is called "reverse telecine" because it is used for 24 fps film material that was transferred to NTSC.)

 

24PA uses a special version of 3:2 pulldown where instead of every third video frame containing a fields from two different film frames, it does some other pattern where I think there's simply an extra whole video frame now and then to convert 24 into 30, which is much easier to remove in post. That's also the reason why you only use 24PA if you plan on removing it -- the pulldown is more "obvious" when you view playback because you can see that repeated whole frame more clearly than the normal 3:2 pulldown sequence. If you need 3:2 pulldown in the final product, for recording to tape for normal NTSC viewing, then you'd remove the 24PA pulldown, edit in true 24P, then create a separate 60i master where you reapplied standard 3:2 pulldown. You have your 24P master in order to burn to DVD, since a DVD player can add 3:2 pulldown for playback on NTSC monitors (which is not necessary if going to a progressive-scan monitor like a computer screen.)

 

The trouble with not removing the pulldown is that once you start making cuts in 60i, the sequence is broken up, making it harder to remove later if necessary.