24/48/72p

C

CMcMahon

Well-known member
This is probably in the wrong forum, but whatever.

So, this is something I've been wondering about for awhile. You have all of these people (and companies) making a huge deal about 24p for it's "filmic" value and whatnot, but yet you run into issues when there's motion involved.

You have cameras coming out that record at 24p, 30p, and 60i/p.

Well, why are they not including a 48p (or even 72p) recording mode? It seems like it would be easier to process a clean image from a 2x (48p) or 3x (72p) source than from 1.25x (30p) or 2.5x (60p), if your final output is going to be 24p...
 
What do you mean by "easier"? I drop my 60p footage into Cinema Tools, click "convert," select "23.976" and it's done. I don't have to do anything else. I would have to do the same with 48p, 72p, or 256p.
 
Well, what I mean to say is that, if you were shooting 48p, you could drop every other frame, whereas if you were shooting 60p, the computer would be dropping some frames and interpolating some others, at least as I understand it.
 
60i is the television standard. 30p is an orphan that few people use, but it exists solely because it was a way to make progressive footage on an NTSC-frame-rate television.

The goal hasn't been about "getting better motion", it's been about making products that are compatible with the prevailing standards.

If you want 48fps for slow-mo, you can get that in most variable-frame-rate camcorders, including the HPX170, HPX300, HPX370, HPX500, HVX200/200A, or EX1.
 
The AF100 almost unquestionably will have 720/48p. And there has been no details of any type related to any announcement of any new Sony camera. There was only an HDV camera with the lens sawed off and a prime stuck up next to it. They didn't discuss it, they didn't talk about features or price range or anything. So there's no way to know what it may cost, what it may do, and when it may arrive.
 
Well, that's cool, then; I had thought otherwise because I'd seen something listing it as having the same modes as my HMC40 (1080i60, 1080p30, 1080p24, 720p60, 720p30, 720p24).

Is that what the deal with that Sony thing was? That would explain why I couldn't even remember the name of it.
 
CMcMahon said:
Well, that's cool, then; I had thought otherwise because I'd seen something listing it as having the same modes as my HMC40 (1080i60, 1080p30, 1080p24, 720p60, 720p30, 720p24).
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It does have all those same modes, but it also has variable frame rates. On all the other cameras, 720/48p is one of the options, so it would seem like a very good probability that the AF100 will have it as well.

Is that what the deal with that Sony thing was? That would explain why I couldn't even remember the name of it.
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I don't believe any name was assigned to it. There was no press release. It's like they brought it JUST IN CASE they needed it, and after Panasonic announced the AF100, they were like ... "hey, find that thing we made and pull it out, so we look competitive too... "

Anyway, undoubtedly they will have to make something to compete, but unless I'm mistaken they didn't announce any details whatsoever.
 
Barry_Green said:
60i is the television standard. 30p is an orphan that few people use, but it exists solely because it was a way to make progressive footage on an NTSC-frame-rate television.
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Not to be disagreeable, but 30p is quite popular and quite common. In fact, very common. It's pretty much all I shoot based upon 1) what I think looks great 2) professional advice and 3) seeing what high-def footage stock houses want and sell. Perhaps you were speaking about films where 24p rules, but otherwise 30p is everywhere I see.
 
If you shoot 48 fps and drop every second frame, or shoot 72 fps and drop 2 out of 3 frames, you'll have the exact same motion cadence -- and the "problems" associated with it -- as you would if you just shot 24 fps.

The same goes for shooting 60i or 60p and converting to 24p.
 
Not sure what you mean here. Shooting 48fps and dropping every other frame, gives you 24p. Shooting 72fps and dropping 2 of three frames, gives you 24p.

Shooting 60i or 60p and converting to 24p, results in compromised motion and issues.

Shooting 48p or 72p gives you the ability to go seamlessly betwen 24fps motion, and 2:1 or 3:1 slow-mo. However, you will have shutter speed issues, since you have to pick one that works for 72fps, and that'll be a lot shorter than what you would normally use for 24p.
 
I am explaining why shooting at 48 or 72 fps and then converting to 24 fps won't solve the motion "problems" with shooting 24p. You can't shoot a higher frame rate, convert to 24p, and then have "smooth" motion because of it. Your end result is still 1 picture every 24th of a second, with the same amount of time and apparent distance between moving objects (which are what causes "strobiness," etc) as it would have been shooting straight 24 fps.

Converting from 60i/p introduces more problems, yes.
 
CMcMahon said:
...this is something I've been wondering about for awhile. You have all of these people (and companies) making a huge deal about 24p for it's "filmic" value and whatnot, but yet you run into issues when there's motion involved.

You have cameras coming out that record at 24p, 30p, and 60i/p.

Well, why are they not including a 48p (or even 72p) recording mode? It seems like it would be easier to process a clean image from a 2x (48p) or 3x (72p) source than from 1.25x (30p) or 2.5x (60p), if your final output is going to be 24p...
Click to expand...

Second that. With BDXL coming out, it should include some of the common frame rates like 30p and 60p, and some that we'd like to see become more common such as 48p and 72p. And for these, can we return to common sense and make them actual 48, and not 47.95? That idiotic 1000/1001 "standard" may have made some level of sense when it was introduced in the early days of color TV broadcasting, but those days are long gone -- that it still hangs around is another example of "we've always done it that way" whether it makes any sense or not. That we didn't kill that off was yet another missed opportunity in the change over to digital TV. Sigh...
 
Bruce Watson said:
Second that. With BDXL coming out, it should include some of the common frame rates like 30p and 60p, and some that we'd like to see become more common such as 48p and 72p. And for these, can we return to common sense and make them actual 48, and not 47.95? That idiotic 1000/1001 "standard" may have made some level of sense when it was introduced in the early days of color TV broadcasting, but those days are long gone -- that it still hangs around is another example of "we've always done it that way" whether it makes any sense or not. That we didn't kill that off was yet another missed opportunity in the change over to digital TV. Sigh...
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The overwhelming majority of TV's are NTSC Standard Def. The switch to digital isn't going to change the fact that most TV's out there in the US can only do 29.975 interlaced and not 30p. Besides, most people get their TV signal via cable or satellite, so the switch to digital broadcasts is meaningless to them.
 
Bruce Watson said:
You say that as if analog TV was still being broadcast.
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It is, over cable.

But even if it weren't, the digital standard is still 1000/1001 and isn't going to change, so that's the way it is. Making cameras which don't shoot with that in mind would be silly. Very small market of people never intending to show anything on TV.
 
David Jimerson said:
It is, over cable.

But even if it weren't, the digital standard is still 1000/1001 and isn't going to change, so that's the way it is.
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Some people don't like change. I get where you're coming from.

But I'm talking about frame rates that won't work with current TV anyway -- I've never seen a TV anywhere in the world that would handle either 48p or 72p, so there's no reason to feel threatened.

Standards start somewhere. Some are arbitrary decisions. Some are workarounds for a problem no one wanted to fix (1000/1001 comes to mind).

But the best standards are built to solve a problem or create a new capability. My favorite example of this is Ethernet. When it was invented, the technology didn't yet exist to make it. But the people who worked it did the right thing -- they defined what it would take to make the thing work well first, then figured out how to make it physical. They also decided that it needed a growth path, so they built that in. As a result the standard has grown an changed over time. As a result, we no longer have "thick-wire" Ethernet (even though at the time, we had in fact "always done it that way"), but Ethernet itself continues to exist.

Imagine what digital TV would have been had the same process been applied. Instead we have a horse designed by committee. Oy.
 
Bruce Watson said:
Some people don't like change. I get where you're coming from.

But I'm talking about frame rates that won't work with current TV anyway -- I've never seen a TV anywhere in the world that would handle either 48p or 72p, so there's no reason to feel threatened.
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Ummm . . . why are you making this personal?
 
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