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24p native: Worth upgrading to it?

cableaddict's picture
Last seen: 3 years 8 months ago
Joined: 04/19/2011 - 9:49pm

The subject of 24pn (native) vs 24pf (or whatever you want to call 24 fps embedded in 60i with pulldown) has been covered extensively all over the internet. So, we all know what it is & how it works. - except the most important issue has never been adequately explained:

What the heck does this mean to ME?

I am trying to decide if I should upgrade my HFS100 to the HFS200. The only real difference is native 24p. The best I can figure, once conversion has been done, the main advantages of true 24p native are:

1: More recording time on the card.

2: Possibly more information per frame, but this is debatable.

3: Possibly less editing hassles, as you don't have to do an intermediate pull-down conversion. - but i depends on what software you use.

4: Some claim that 24p native lets you pan with no stuttering. - not confirmed.

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According to some (confusing) reports, 24p native can actually be a hassle, because some software (Vegas?) doesn't support it. I have yet to actually edit any 24pf footage, so I am not sure how much of a hassle 24pf is.

Man, am I confused. Can someone shed some light on this subject?


Charles Schultz's picture
Last seen: 1 year 8 months ago
Joined: 10/25/2010 - 10:38pm

Allen, it all depends on where you show your videos at, are they online, tv, movie theaters? As far as I know, the only place that uses 24p anymore is in movie theaters. Most TV stations use 60i for HD and I believe it is 30i for standard def. Personally, I never use 24p as most of my vids are for the web and tv. I do have one commercial playing in the theaters but it was shot at 30p and most of those are shown digitally.


cableaddict's picture
Last seen: 3 years 8 months ago
Joined: 04/19/2011 - 9:49pm

Interesting point. I thought you could upload 24p to YouTube, among other sites. - Same for personal websites.

Also, some high-end consumer LCD's & plasmas do native 24p, and supposedly picky viewers can see the difference.

Anyway, I'm not so concerned with the delivery end of things, (I can always bump it up or re-wrap it) just the editing issues, and the overall quality of the product at the final editing stage.

For instance, I know that most folks transcode with Neoscene before editing in Vegas (I am using Vegas Pro for now) because there are (were?) problems with Vegas' internal de-interlacing. However, supposedly this takes up a HUGE amount of hard drive space. I will routinely be editing 4+ hours of continuous footage, so this is a big concern of mine.


cableaddict's picture
Last seen: 3 years 8 months ago
Joined: 04/19/2011 - 9:49pm

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In addition to my previous questions, let me ask in a different way:

Other than the cost of upgrading my camcorder, are there any negative factors regarding recording / editing 24p native?


Charles Schultz's picture
Last seen: 1 year 8 months ago
Joined: 10/25/2010 - 10:38pm

I have not worked with Vegas Pro so I do not know if there would be any issues in editing. As far as I am concerned, there are no negative factors using it, I just prefer 30p as most of my vids are on YouTube. When you upload to YouTube, they convert it for you so it is really up to you.

What kind of videos are you working on that are 4+ hours long? Those must be some huge file sizes and rendering times.


Rob Grauert's picture
Last seen: 10 months 3 weeks ago
Joined: 02/16/2008 - 10:47pm

Charles,

Nothing on television is 30i because there is no such thing as 30i. Everything that is broadcast is 60i.

Allan,

Charles is right. Whether you want native 24p or 24p with pulldown depends on what you're doing in post and what you're delivering to.

Yes, you can upload 24p to the web, but computer screens generally work at 30p. So 30p is ideal. If you what you're doing, you can work in native 24p and add the proper pulldown when you're finished editing so you get 30p for the web, but maintain the look of 24p.

Disregard anyone who says you should go with native 24p simply because higher end TVs support native 24p and some viewers will be able to tell the difference. Anyone who sits in front of the TV and complains about the frame rate is a tool.

24p doesn't cause stuttering either. Sure, it's a slightly choppier, blurrier look, but that's different from stuttering. If the editor is experiencing stuttering playback, they're computer is not properly equipped.

I know that most folks transcode with Neoscene [...]because there are (were?) problems with Vegas' internal de-interlacing. However, supposedly this takes up a HUGE amount of hard drive space.

This doesn't make sense all over the place.

People transcode because Vegas doesn't de-interlace well? You're talking about working with 24p. It has nothing to do with interlaced video.

Second, even if Vegas deinterlaced your footage, de-interlacing shouldn't really be changing the file size.

Third, if it did make larger file sizes, so what? Get a bigger hard drive. You're talking about upgrading a camera but you don't have money to throw down for a larger hard drive?


Rob Grauert's picture
Last seen: 10 months 3 weeks ago
Joined: 02/16/2008 - 10:47pm

I forgot to mention that pulldown was invented so you could record 24p to tape. You actually want to edit it. Generally, you want to be editing footage that is actually 24p, but if the only think you're doing is cutting, it's fine to ingest your footage as 60i, treat it as 60i through post, and then export it as 60i. 24p with pulldown is in fact 60i, which is why you treated as 60i.



shippocaio's picture
Last seen: 6 years 6 months ago
Joined: 06/12/2008 - 7:24pm

"Anyone who sits in front of the TV and complains about the frame rate is a tool."

LOL. So true. Besides, if someone is really paying that much attention to the frame rate, i think they should get a life! :)

You made me laugh so much rob!


cableaddict's picture
Last seen: 3 years 8 months ago
Joined: 04/19/2011 - 9:49pm

Thanks for all the info, guys.

Rob, you misunderstood my point / question re Vegas: The problem is with 24pF. That is, 24 wrapped at 60i with pulldown.

I'm trying to determine if Canon's new "native" 24p negates this problem. Panasonic's does, and even gives significantly more recording time, but I am getting confusing info from Canon tech. I think their marketing dept is pulling a fast one. 2 separate techs said that even the 24p native is wrapped at 60i, which makes no sense. They also say that Vegas will see the data as true 24p and not require de-interlacing. - which makes no sense if it's @ 60i. (unless I'm missing something.

Intersting facts:

Canon's 24pf (wrapped) and 24p (supposedly native) both give the same maximum recording time. That makes no sense unless the native 24p is recording vastly more data per frame, but it isn't.

The only other significant technical change between the two Canon's is that the HFS200 offers a "1/2" minimum shutter speed option, whereas the HFS100's minimum is 1/6. Maybe that has to do with true 24p, and the Canon techs were wrong?


Rob Grauert's picture
Last seen: 10 months 3 weeks ago
Joined: 02/16/2008 - 10:47pm

According to B&H, there are 2 24p recording modes for the HFS200 - "Native 24p Mode" and "24p Cinema Mode." According to them, Native 24p Mode is actually 24 frames per second, while 24p Cinema Mode is 24p with pulldown, making it 60i.

"They also say that Vegas will see the data as true 24p and not require de-interlacing. - which makes no sense if it's @ 60i."

Since you're talking to tech support and asking about a consumer level camera, they're probably over simplifying it, which is causing more confusion. What they might mean when they say, "Vegas will see the data rate as true 24p," is that the video playback will look like 24p even though you're playing back 60i, which you already know. And when they say, "and not require deinterlacing," they probably mean the footage doesn't need a pulldown removal to achieve the film-like frame rate.

So, in you're first post you said you're trying to figure out whether you should upgrade from the HFS100 to the 200,, And you also stated that native 24p is the only real difference between the two. Unless you have a good reason for NEEDING native 24p, I don't see a reason to spend $650. But hey, I won't stop you from stimulating the economy.


cableaddict's picture
Last seen: 3 years 8 months ago
Joined: 04/19/2011 - 9:49pm

"Unless you have a good reason for NEEDING native 24p, I don't see a reason to spend $650."

Well, yeah. - hence this thread. - except there's a very good answer posted above. Plus the shutter-speed issue, which has yet to be clarified. I also still don't have an answer regarding what the HFS200 is actually recording in its "24pn" mode.


Rob Grauert's picture
Last seen: 10 months 3 weeks ago
Joined: 02/16/2008 - 10:47pm

Sorry, I didn't answer your shutter speed question because shutter speed has nothing to do with enabling a camera to shoot native 24p. Generally, you're not going to be shooting at either of those shutter speeds anyway. They're too slow.

Does the HFS200 have a mode that is actually called 24pn? Because I thought the information I pulled from B&H would have cleared up your confusion. The HFS200 has two 24p modes. One is native, one is recorded with pulldown.


cableaddict's picture
Last seen: 3 years 8 months ago
Joined: 04/19/2011 - 9:49pm

No, the jury is still out on what Canon is currently giving us.

Regarding shutter speed: I was responding to info I got on another forum, wherein someone said motion stuttering was typically caused by a too-slow shutter speed. (I have no idea, though since film doesn't stutter, one can assume that the problem is NOT 24 fps) This guy said that shutter speed should ideally be 2X the frame rate. I got confused and thought maybe Canon's "1/2" setting meant a 1/48 shutter when shooting at 24 fps.

Reading the (confusing) manual carefully, it seems to simply mean 1/2 second. Oddly (?) there is no 1/48 shutter option, but I'm not going to worry about this.


Rob Grauert's picture
Last seen: 10 months 3 weeks ago
Joined: 02/16/2008 - 10:47pm

No, slowing the shutter speed does not cause your image to stutter (neither does increasing the shutter speed). Instead, slowing the shutter speed will create more motion blur because the image sensor remains sensitive to the light for a longer period of time. So if the HFS100 had a maximum shutter speed of 1/6, and the HFS200 has a maximum shutter speed of 1/2, all they're telling you is the HFS200 is capable of shooting at a slower shutter speed. That's all. It's just plain irrelevant when determining 24p capability. Make sense?

Your source is correct in saying that the shutter speed should generally be twice as fast as the frame rate, though, unless you have a reason for changing it.

I'm not sure what else to tell you, though. B&H seems pretty clear - one mode is Native 24p and the other mode is 24p with pulldown. Isn't that what you wanted to know? What unanswered questions are you left with?


cableaddict's picture
Last seen: 3 years 8 months ago
Joined: 04/19/2011 - 9:49pm

Rob, you keep not understanding my points / questions. Whatever, I appreciate you time, regardless.

I also have my answers, from various sources, and I am upgrading.

<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 10.0px Verdana;">Evidently there are two basic ways to implement 24p native. One way uses a lower bitrate, with each frame containing the same amount of data as with 24p wrapped at 60i. The other way is to still use the highest bitrate possible. Some people say that a higher bitrate helps minimize the dreaded "judder" problem with 24 fps video, which makes sense since it doesn't happen with film. Some also say that (depending upon implementation) it is possible to get better low-light performance with true 24p native.
<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 10.0px Verdana; min-height: 12.0px;">
<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 10.0px Verdana;">Now, as best as I can figure, most of the consumer / prosumer Panasonics are doing 24pn with lower bit rates, (you get a lot more recording time) while Canon is using a high bit rate. For instance, in the Canon HFS200, you get the same maximum recording time with 24pn as with 24pf. - Same bit rate. This probably confused the the Canon "techs" as it's the same amount of data as 60i.
<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 10.0px Verdana;">
<p style="margin: 0.0px 0.0px 0.0px 0.0px; font: 10.0px Verdana;">Will it look better? I dunno, but the new camcorder holds 2 SD cards, so twice the recording time at max bit rate, and that is critical for what i do. I guess I be reporting back here once I have had a chance to run some of my own tests.



cableaddict's picture
Last seen: 3 years 8 months ago
Joined: 04/19/2011 - 9:49pm

Questions were / are

1: Difference in ease of editing. (speed, size of the files, etc) - Answered now.

2: Difference in video quality. - A source of massive confusion. I believe my post, above, is the correct answer.

Got a little off-track with the HSF200 format issue, (sorry!) thanks to Canon's tech absurd support. As mentioned, I'll be answering that one myself, soon, & will report here.



UnitedNerds's picture
Last seen: 4 years 1 month ago
Joined: 11/12/2010 - 2:19pm

This topic is making me laugh a lot. It seems to me like it is not worth it to get the HSF200, at least not for the reasons you are looking into it. On the other issues, you might be worrying a bit too much. It is good to understand what your software and camera is doing but you can go overboard. If you can work with the camera and the footage looks the way you want it to, that's all you need to know! Most technology these days handles those issues you are worrying about behind the scenes and shouldn't affect the outcome of your videos too much.


Dave Haynie's picture
Last seen: 4 years 8 months ago
Joined: 03/29/2010 - 4:12pm

Rob: the video refresh rate for a PC is relatively moot. Most online video streaming services, like YouTube, transcode your bideo, and not just in format, but also frame rate, to optimize their storage. It's common for online material to be rendered to 24p for delivery. The monitor refresh rate doesn't matter, because your playback isn't beam-synched to the monitor anyway. And PC displays are universally progressive, but never below 60p. LCDs are generally 60p, CRTs are usually 75p-85p.

Everyone: 24p stored as 60i is still very much real 24p. This is an old timey trick from the tape era. When DV was defined, it was with a fixed frame rate, bitrate, and tape speed. Period. And no real consideration for anything but 60i/50i. So when camcorder manufacturers wanted to add 24p, they were forced to map that 24p into a 60i tape format. It's still real 24p, just broken up into fields, some of them doubled. The only loss of quality is that the compression CODEC is run on the field, not the frame... and you're storing redundant data, versus what could have been stored if you did a natural 24p compression. Both are fairly minor issues.

If your NLE is sophisticated enough, it'll automatically detect the pulldown and ignore it, so you only ever see 24p. Vegas these days is hit or miss... it does this well on DV with most cameras, not so much with AVCHD. It's fairly stupid for camera companies to still do 24p in a 60i wrapper for tapeless formats, but some persist.

You do actually need more bits per frame to do 24p well, so there can be an advantage to native 24p. The reason is the way MPEG family CODECs (including MPEG-1/2, AVC, and VC-1) work. In these, you store one independent frame (I-Frame), not much different than a JPEG photo. Then you store 14 more frames (usually), which are composed of differences from that first frame. A motion estimation algorithm runs on the difference between frame N and N+1, and encodes essentially how to move things from frame N to N+1 to restore the N+1 image. The reason you want a higher bit budget here for 24p is simple: you're going to get more motion between frames at 24p than 30p or 60p. The motion estimation stuff is the same, but the bulk of what's stored is the difference... the encoder applies the motion vectors to frame N, compares it to frame N+1, and that difference also has to be stored. If there's too much motion, that difference will be overcompressed, and the result fairly ugly... that's when camcorder video starts to "pixelize" (not really, but that's what people like to call it.. you start to see the DCT blocks).

I don't think the difference between 24p and "24p in a 60i wrapper" is enough of a change to justify a camera upgrade, alone. But it's a valid issue when factoring in the features of one camera vs. another.