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-   -   Why not shoot in 24p Always? (https://www.dvinfo.net/forum/canon-vixia-series-avchd-hdv-camcorders/95340-why-not-shoot-24p-always.html)

Scott Turkington May 29th, 2007 11:50 PM

Why not shoot in 24p Always?
 
So is there any reason not to shoot in 24p all the time? As I understand it, at least in 24p it puts the 24p video in a 60i video stream that you must do a 3:2 pull down to extract the 24p. But if you're busy and you don't want to extract the 24p you don't have to, but it's there so you can always grab it at later if you need too? If it wasn't shot in 24p you can't ever get your video to there so shouldn't you just shoot in 24 all the time? Am I correct, does this sound right?

If I'm not what are the negatives of shooting in 24p all the time?

Thanks guys!
Scott

Glenn Thomas May 29th, 2007 11:57 PM

Well, if you were shooting something you wanted to appear in slow motion you'd shoot interlaced and then interpolate the fields in your editing app so that each field plays back as an individual frame. That's the only reason I can think of for not shooting in 24P/25P all the time.

Actually, maybe capturing sports or news footage may benefit from 60i/50i, but I doubt too many people with HV20s would be using them for such purposes.

Scott Turkington May 30th, 2007 12:15 AM

In 24p mode doesn't the HV20 automatically shoot the 24p inside a 60i video? So even in 24p you actually get a 60i video so it would still work for sporting. You just later extract the 24p from the 60i?

If that's the case then I guess the only reason then would be to shoot slow motion videos using the technique you described?

Thanks for the reply!
Scott

Glenn Thomas May 30th, 2007 12:28 AM

The 24P is embedded in a 60i stream, but is still 24P. It just appears interlaced due to how the 3:2 pull down works. Somebody correct me if I'm wrong here?

25P is a lot simpler as both fields = one progressive frame.

Austin Meyers May 30th, 2007 12:34 AM

when the 24p is put into a 60i stream it just means the processor in the camera duplicates frames/fields so 25% of the data is just repeated, but is necessary to fill the space on the tape. so regardless of whether you remove the pulldown or not it won't look good on fast motion things.

at first i thought i would always shoot 24p but after having the cam for a little while and shooting nearly 40 hours with it, i'm probably shooting half and half, anything handheld or fast motion i'm shooting 60i, whereas i save the more artsy stuff for 24p because of the nice filmic look. if you're shooting a lot of handheld i would shoot in 60i as it's much more forgiving to camera movement. but you should just go out and shoot the same scenes with both and then compare them in post. you'll learn fairly quickly what you like, and what is most pragmatic for what you're shooting.

Scott Turkington May 30th, 2007 01:02 AM

great, thanks for that insight :)

Scott

Euisung Lee May 30th, 2007 01:46 AM

Sure why not ;)
 
If 24fps is the ultimately ideal frame rate for you you should always use 24. Like Glen said maybe except when you need to shoot slowmo or a sporting event with clarity.

Not everybody will find 24fps ideal I think. But as for me 24 is the dream fps and I'm always shooting in 24p, which is why I got hv20 in the first place :)

Jay Cowley May 30th, 2007 07:33 AM

Quote:

Originally Posted by Scott Turkington (Post 688778)
So even in 24p you actually get a 60i video so it would still work for sporting. You just later extract the 24p from the 60i?

but thats not the point. If CBS-HD decided to begin covering their football games in 24p this year, you'd watch the first game and it would be mess. The crowd would be juddering along, you'd have a hard time keeping control of the ball, it would just be annoying on the eyes.

They shoot sports/talk shows/news/ in 60i for a reason. It does the best job accurately re-producing the content to your TV screen. 24p works much better for effect in drama, telling a story, it gives whatever your showing a more 'authentic' feel, but it's certainly not going to make it feel like your sitting in the stands at a football game.

Blake Calhoun May 30th, 2007 08:45 AM

Yep, 60i makes the footage feel "live". 24p makes it feel like a "movie". A few years back MTV tried broadcasting their Music Awards in 24p and viewers hated it... felt like it was "old" or a "documentary" - not like it was happening right then.

However Jay I must disagree about the "judder" you refer to... ever watch NFL Films??? That's some of the most beautiful stuff you'll ever see... handheld 16mm following the football through the air, panning the crowd, etc. All of course shot at 24fps and with no "judder".

EDIT: Of course a lot of that 16mm footage is shot at 48fps and even slower. :)

Enea Lanzarone May 30th, 2007 08:49 AM

Quote:

Originally Posted by Jay Cowley (Post 688896)
They shoot sports/talk shows/news/ in 60i for a reason. It does the best job accurately re-producing the content to your TV screen. 24p works much better for effect in drama, telling a story, it gives whatever your showing a more 'authentic' feel, but it's certainly not going to make it feel like your sitting in the stands at a football game.

Very well said, Jay.

A few years ago I read the following statement (don't remember who said it and where) on the net:

Interlaced (60/50i) is what the eye sees and progressive (24/25/30p) is what the mind sees.

Austin Meyers May 30th, 2007 09:01 AM

Quote:

Originally Posted by Blake Calhoun (Post 688943)
However Jay I must disagree about the "judder" you refer to... ever watch NFL Films??? That's some of the most beautiful stuff you'll ever see... handheld 16mm following the football through the air, panning the crowd, etc. All of course shot at 24fps and with no "judder".

correct me if i'm wrong but aren't most of the NFL films shot overcranked? thus the super smooth slow-mo... i've worked on a a fair amount of 35mm commercial shoots, and they almost always shoot overcranked (usually 48fps)

Johan Bunis May 30th, 2007 10:03 AM

What I have experience the HV20 have more difficult to find focus in 25P(24P then 50i/60i...

Scott Turkington May 30th, 2007 11:11 AM

Quote:

Originally Posted by Enea Lanzarone (Post 688948)
Interlaced (60/50i) is what the eye sees and progressive (24/25/30p) is what the mind sees.

I like that, that's a perfect way of describing it...
Scott

Thomas Smet May 30th, 2007 04:44 PM

This is why I have always considered 50p (720p) to be the best format overall to work with.

1. It can convert to very high quality 1080i by interleaving every other 50p frame.

2. Super high quality 25p HD or SD by dropping every other frame.

3. Great 24p HD or SD by dropping every other frame and time shifting.

4. Great 50p if you ever do need it.

5. Great clean slow motion for 25p or 24p projects.

6. And finally if you really need it you can convert to a 50i SD for normal broadcast work.


50i is in second place in terms of quality except for maybe 1080p conversions. 1080i 50i down converts pretty good to 720p and lower resolutions.

About the only format you can't really get from 50i/50p is 60i or 30p.

by shooting in a 50 fps format however you have the choice of going slow motion for a shot that might look a little too jerky at 24p or 25p.

Luc Fender May 30th, 2007 07:29 PM

The 24p mode does exhibit warping with quick movements...
Search this forum there's an example video... I only would use it to get better low light quality.


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