24p vs 30p vs 60p vs 60i

J

Jonathan12uiz

Well-known member
Ok everytime I try to search it get all these conversion methods, what I really want is an explaination.

So what I believe is that: *edited - updated according to NURBS*

24p is used for cinema
30p is used for home video
60p is used for sports

Is this correct?

Also why is it easier to turn 60i to 24p than it is to make 60p or 30p into 24p?
 
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It is not easier (nor better) to turn 60i into 24p, versus 60p into 24p. Progressive is always better than interlaced.

But it's infinitely better and easier to turn 60p OR 60i into 24p, than it is to turn 30p into 24p. More motion samples give you more information to work with.
 
Wow that really clears things up and makes sense! Should you then shoot everything at 60p then conform to 24p since i remember reading the gh1 doesnt record B frames. Wouldnt this give you more info(better image? to work with? Sorry im am learning here and this just hit me!
 
The 60p-to-24p conversion can look pretty good, but if your goal is 24p you should be shooting 24p in the first place. In some things 60-to-24 looks fine, but for others it just doesn't work that well -- like a smooth dolly move or a smooth pan, for instance.

The problem with the GH1 and 720p vs 1080 isn't one of B-frames, as neither mode has those. The problem is that the GH1 embeds its 1080/24p within a 1080/60i data stream, so you have to strip out the pulldown if you want to edit native 24p. It's a minor inconvenience in that you have to run something like Cineform Neo Scene to convert the footage, but once you've done so it works fine.
 
30p-to-24p conversion allows clean 0.8 slo-mo, while 60p-to-24p allows clean 0.8 and 0.4 slo-mo. Having 60p (or 60i for that matter) offers more choices for slo-mo than 30p.

If you don't need slo-mo, then converting frame rates always degrades quality of your video; shooting 60p just to convert it to 24p has no sense whatsoever. Instead you should shoot 24p, even if it is recorded within 60i, then you should remove the pulldown with either Cineform, or with BIC/DNxHD, or with Procoder or with some other tool and codec of your choice. Do not edit 24p-in-60i, the final result will not look good on the Web, and will look just passable on a TV.
 
Ok so just shoot 24p if looking for that film look. better to originally have 24 than to convert to.

well I have a few more questions....

why is 24p designated for film, is it just because it's always been that way?
same for 30p for home video and 60p for sports?

also if 24fps is what is used for cinema, what about all the action movies with all that action on screen? do they shoot at high fps then convert down to 24p? or do they shoot everything in 24p?
 
Jonathan12uiz said:
why is 24p designated for film, is it just because it's always been that way? same for 30p for home video and 60p for sports?

also if 24fps is what is used for cinema, what about all the action movies with all that action on screen? do they shoot at high fps then convert down to 24p? or do they shoot everything in 24p?
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Google is your friend.
 
Ok so what i've gathered is that 24p is just what old film cameras transfered as...

as for why 30p and 60p are designated for home and sports, I could not find any background.
Other that the fact that 60p has more fps so its great for fast action in sports.
 
24p is the framerate that all motion pictures are shot at -- it's just the way it is. Always has been (since the advent of sound). Projectors run at 24fps. The whole industry is geared for 24fps.

As for action films -- if it's realtime action, it's shot at 24fps. If it's slow-motion, that means it was shot at a faster frame rate (like 60p) and then played back at 24fps.

30p is kind of an "orphan" frame rate that doesn't have a whole lot of reason to exist. It makes for a lousy transfer to film, to PAL television, or to 24p video for a DVD. It's fine for mild slow-mo, but I've got pretty much no use for it otherwise.

60p/60i give you the "live" look. Watch any sports broadcast and what happens on the screen looks the same as it does in reality -- it's "live". It's also used for the news, for soap operas, for live broadcasts, press conferences, anything that's supposed to look "live".

24p gives the "film" look, because films are shot at 24 frames per second, and 24p video gives that same motion cadence.
 
Barry I have a question for you... so I shot some stuff at the GH1's 24p which is that wacky 60 filed split thing. Now I need it to go to an Avid timeline at the show I work for at 1080i 59.97 DNxHD 145 .... sooooo whats the best way to do this. the problem is that if I use the footage as is it looks very jerky because of the way they do the pull down in camera. So I can run it through cineform for reassembly of the 24p and then I'm not sure where to go with it to batch convert it to something the avids here at work can use. I need to fit into THEIR workflow I can not re invent the wheel here. Any suggestions would be great.
 
No, don't change anything. Editing it on a 1080i 59.94 timeline is exactly what you're supposed to do. That's how film was edited for decades before native 24p timelines came about.

The pulldown doesn't add any jerkiness; if the footage looks stuttery it was probably panned too fast or otherwise didn't get shot properly for 24p. 24p-within-60i is extremely common; if you've ever watched a movie on television, that's what you saw -- 24p within 60i.
 
I get that... but I thought that the split the camera does was not the standard 3-2 pattern but a much different one so the footage ends up looking funky.
 
Barry_Green said:
No, don't change anything. Editing it on a 1080i 59.94 timeline is exactly what you're supposed to do. That's how film was edited for decades before native 24p timelines came about.

The pulldown doesn't add any jerkiness; if the footage looks stuttery it was probably panned too fast or otherwise didn't get shot properly for 24p. 24p-within-60i is extremely common; if you've ever watched a movie on television, that's what you saw -- 24p within 60i.
Click to expand...

Wouldn't it be easier to go with native 24p production and apply pulldown during broadcast (if even broadcast)? Surely making a black box (or even software nowdays) that just does pulldown is pretty trivial for such a task. Seems like such a hassle to jump between these framerates. Not to mention all the mistakes that get made.
 
shaocaholica said:
Wouldn't it be easier to go with native 24p production and apply pulldown during broadcast (if even broadcast)? Surely making a black box (or even software nowdays) that just does pulldown is pretty trivial for such a task. Seems like such a hassle to jump between these framerates. Not to mention all the mistakes that get made.
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His editor wants a 1080/60i timeline. Easiest way to go is to give them the footage in 1080/60i format -- which is what the GH1 records. 1080/24p embedded in 60i.

For everyone else, yes, editing 24p is the right way to go. But the deliverables requirement for this particular poster was 1080/60i.
 
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