-
24p vs . 30p
hi guys! since im new to this business im not really familiar with 24p. is it really such a big aesthetical difference between 24p and 30p? i would love to hear some opinions concerning that topic!
thanks a lot
florian -
7 Replies
-
-
Florian,
HD video really started to catch on when Sony obliged George Lucus in providing the first Cine Alta camera that offered 24p. It has been since then that a “video” camera could imitate (and ultimately replace) film cameras in creating identical motion on screen.
With the additional electronic wizardry of “cine gamma” where the video camera can now more closely also imitate the reproduction of tones similar to film (a greater ability to compress the highlights while at the same time reaching into the shaddows) these new HD cameras are finding wide acceptibility because of the cost savings and their subjective similarity to film qualities. Ultimately, when the imagers are able to equal film resolution (4K) and recording techniques evolve that allow uncompressed mastering you’ll see many (if not most) cinemas convert to digital projection in order to take best advantage of a end-to-end digital solution.
Yes there is a difference between 24 and 30p aestheticly; just look at it yourself. This is not to say that 24 is better, it just is what film does. 30p is actually smoother and for that matter 60p might even be the “holy grail” but recording that much information creates a bottleneck. I was lucky enough to have seen a 60fps implimentation of film called “Showscan” many years ago at a cinema in Westwood Village. It truely was spectatcular, but I remember that my impression of it was that it resembled television more than film (granted a high resolution version), but due to it’s costs that format never was adopoted.
The 24fps film speed was implemented in the first place to accomodate the reproduction of sound; prior to sound, silent movies were shot and projected at 16fps, and this speed was chosen to be the slowest possible frame rate that human “persistance of vision” would allow to recreate flickerless viewing of projection of moving images in a dark theater. Even then the cost of film and processing figured highly into the calculation.
Ultimately with these new HD cameras, producers must make intellegent descisions regarding what speed to shoot. These are based primarily on the anticipated exhibition platform; if for “film-out” to the cinema, 24p is the natural choice, if for progressive DVD (or the internet) 30p makes a lot of sence and if for networks that have chosen the 1080i standard then 60i is for you. Sometimes of course producers are not sure, or want to hedge their bets, then some compromise takes place. The same discussion and consideration must often also be engaged in determining 4×3 or 16×9 formatting, or protecting both (although this has also been done in film production for years).
24p is often chosen because replacing (immitating) film and saving money are both attractive alternatives; also the conversion to 25 European PAL standards is most seamless.
For your particular project, you should consider all of the above, but do not make a decision without testing both speeds and critically viewing the results on the viewing platform your project will end up on. Only then will you have made an informed choice.
JS
-
Hmmm
And you were able to explain this in only 2500 words…
Well done -
Thanks John for a terrific response!
Re: Florian’s original question…
From my personal experience, I like the look of 30p more than 24p because:
1. I don’t really like the look of 3:2 pulldown (ie. converting 24fps into 30 fps for US video). I can see the uneven motion during pans and the interlaced frames that are created in the process. By shooting 30fps motion is evenly paced, shutter motion blur is close to the natural look of 24fps, and there are no interlaced frames created for US tv viewing when distributed at 60i
2. 30fps offers more picture information per second and the effect is kind of like shooting with more pixels in the camera. I too remember Showscan which was 35mm film shot and projected at 60fps and it almost had the look of IMAX, though with stobing motion due to the short exposure required by a movie camera running at such a high speed.
The downside of shooting at 30fps is that frames must be dropped to get to 24fps for US theatrical viewing or to 25fps for European TV or movies. Dropping the frames looks much worse than adding frames from 24fps to get to 30fps when needed.
So, when I shoot knowing that the project will only be seen in the US on TV or video or the web, I usually shoot at 30fps. If anything else is a possibilty, I shoot at 24 fps for the most flexibilty.
I wish I could shoot my Varicam at 60fps and distribute at 60fps as well. Because I can turn off the shutter on the digital camera, it won’t strobe like showscan did and look very nice in playback. Of course, I’ll have to play back my movie at home on my Panasonic monitor that displays 60p and I’ll be the only one to enjoy it…….
-bruce
-
[firewireflow] “is it really such a big aesthetical difference between 24p and 30p?”
As my friends John and Bruce have commented on there are many viewpoints, I am a 24 frame kinda guy, even with some of the issues related to working in Post in 24p (as 23.98, very rarely as 24.0)
on the variable frame rates – you get optimal timing from your offspeed materials when working at 24p, and for those with a film background it is a simple translation.
As JS mentioned 24 is considered a universal format- but he forgot to mention that when producing DVD’s 24p frame can be directly translated to disk at 23.98 and the DVD player will insert the additional frames for NTSC content – this means that you can have 20% more content on the same disk -or 20% better compression for the media- less frames mean more space on the disk.
Additionally 24p content can be played back at 12 fps over the internet (30p at 15pfs) for higher quality or faster DL’sAs a post guy, I prefer cutting at 24p for the lower bandwidth and less volume for my storage. My hardware has the ability to add the pulldown back in for SD or even 29.97 HD playback.
gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows -
[firewireflow] “is it really such a big aesthetical difference between 24p and 30p?”
As my friends John and Bruce have commented on there are many viewpoints, I am a 24 frame kinda guy, even with some of the issues related to working in Post in 24p (as 23.98, very rarely as 24.0)
on the variable frame rates – you get optimal timing from your offspeed materials when working at 24p, and for those with a film background it is a simple translation.
As JS mentioned 24 is considered a universal format- but he forgot to mention that when producing DVD’s 24p frame can be directly translated to disk at 23.98 and the DVD player will insert the additional frames for NTSC content – this means that you can have 20% more content on the same disk -or 20% better compression for the media- less frames mean more space on the disk.
Additionally 24p content can be played back at 12 fps over the internet (30p at 15pfs) for higher quality or faster DL’sAs a post guy, I prefer cutting at 24p for the lower bandwidth and less volume for my storage. My hardware has the ability to add the pulldown back in for SD or even 29.97 HD playback.
gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows -
Interesting thread.
This is a good occasion for me to ask these few questions and put forward some thoughtd on the subject.
Am I wrong in saying that the “film look” part of the panasonic cameras have nothing to do with 24p?
I’m going to put down a few conclusions I have come to, and I would like to know your thoughts and also know if my perception of the subject is wrong.
Ever since I saw the first shots to come out of a DVX 100 at 24p a few years back, My first thoughts were: “I like this cinegamma feature, but could someone get rid of this awfull strobing!”. I feel the same now when I see 24p HD.
I love working in progressive and I love the “non-ntsc video” gamma but I dont understand what there is to like or that compares to film in the 24p strobing.
Here is my technical interpretation, tell me if I’m wrong.
(This applies to projects being finished for North American TV, I know and understand that 24p is most appropriate for film delivery)
If we do the math, every 24p camera availlable today (exept the Sony 900) have a timebase of 59.94. Therefore when shooting 24p the camera actually captures a frame at an exposure of 1/60th and marks it for playback for the duration of 1/24th. Then the 3:2 pulldown, etc… is then applied for playback on video systems.
On the other hand, a film camera running at 24fps, given the fact that the shutter be at 180, captures a frame at an exposure time of 1/48th and is played back at 1/48th.
Film plays back motion at the same rate that it was captured in realtime, outputing a sequence of contiguous moments in time, blurring motion that was faster than 1/48 of a sec.
The 24p video camera takes a short exposure and plays it back at a slower than it’s realtime capture rate, then, it skips to another “short” frame taken at a non-contiguous moment in time and repeats the process. This gives you choppy movements in your footage that you dont get when playing back 24fps film even on video with 3:2 pulldown.
This is what my eyes see when I look at 24p. And when I look at a still frame from digitized film footage and compare it to a still frame of “film gamma” HD, I love what i see in HD no matter what the recorded frame rate was, so this has nothing to do with 24 or 30 fps playback or record. Also, when you need to time strech your footage, 24p is even choppier that you can’t really go under 70% of real time and still have a watchable motion.
Therefore, I’m in favor of 30p when working exclusively for TV or DVD deliverable projects and I tend to discourage the use of 24p in such cases.
Hence my conclusion is that 24p for video has nothing to do with “film look” and is more of a nuisance than a “special feel”.
I have had countless philosophical debates on these issues, but never with people that actually had the sufficient technical understanding of the subject matter.
Please get back to me on your opinions of my hypothesis.
Thanks
Reply to this Discussion! Login or Sign Up