24f(p) or 60i for Documentary?
 

Hey guys,
I am going to start shooting a doc on tuesday and I am not sure which frame rate to shoot in. What are your suggestions for a video will be about a marathon ocean swim in the Santa Barbara Channel? There won't be too much motion, aside from the handheld footage I shoot on a boat. Do you know if i can mix 24p footage with 60i material in an NLE like Final Cut Pro? Any help would be great, thanks!
-Steve

Best to shoot in 60i since a 24p clip in a 60i timeline will have mis-matching frame rates for fades and motion animations.

What about dropping a 60i file into a 24p timeline?

Unless you are going to film why do you want 24p? 24P has so many ways of making video look really bad on progressive displays that I really wonder why anyone would want to use it at all. The juddery video is getting more prevalent on cable that a lot of shows to me are becoming unwatchable. We will start to see more 120hz LCD on the market designed to take out the juddery motion and interpolating the extra frames that the camera didn't take so that the camera person could say they shot 24p!!!! A case of the consumer wanting smooth motion satisfied by the manufacture providing technology to cover for the shooting technology of producer of the program!!!!

Ron Evans

Shouldn't a progressive movie looks just fine on a progressive display? Anyways, I wanted to shoot in 24f (canon's version of 24p) for the filmic look that everyone seems to be after these days. Also, I plan on submitting it to a film festival and they suggest shooting in 24 fps. Also, sites that offer HD video sharing, like Vimeo play 24p files much smoother than 60i. Another question however: is 24p okay for distribution on DVD?

Progressive displays in North America refresh at 60hz. It isn't possible to divide 60 by 24 and get an even number. So to display 24p the display has to do something to the input to make it work. Normally repeating frames( 3,2 pulldown), but not every frame so that the motion is not uniform. The displays that are 120HZ are able to display( 120/24 = 5) however most of these displays also interpolate the extra frames,that weren't there, to get 120 frames a second. So the motion you were after with 24p is poorly presented on most TVs, either introducing judder or interpolated to a smooth 120 fps. IF you are going to film that is very different. Film gets projected at 24fps with normally a 3 blade shutter giving 72 flashes a second. No adulteration of the frame rate just raising the flicker rate to make it appear like moving images to a human being ( a fly would still see it as a series of stills). There is a lot more to the film look than 24 p. Camera motion is critical( as little as possible), shallow depth of field ( because the backround will stutter and it's best made out of focus) avoid motion across the scene ( it will enhance the stutter problem) etc etc.
If you are going to shoot for video shoot 60i. If you want to make a film but shooting video as the source is cheaper shoot 24p, but don't shoot as if it was video, shoot as if you are using a film camera.
As you can tell I am not a fan of 24p. To me its a bit like buying a modern car and insisting it ride like a Model T Ford!!!! 24fps for film was a limitation of technology and investment of the last century. A combination of how slow a film could be run and still have a reasonable sound track and still not break the bank in terms of film distribution costs to all the movie houses. None of the limitations exist today so I see little reason to continue to follow a path set by movie house investment of the last century. For me the answer is high frame rate high definition 60p, it can be displayed by all the current progressive displays at least at 720p and conversion to 30p for the WEB is also easier and will have none of the stuttering issues of 24p.

Ron Evans

Jack, You are supposed to remove the 3:2 pulldown before editiing. If you do this, what your are saying won't happen.

Steve,

IMHO, if your subject is fast moving or the camera will be doing quick pans, then consider 60i. Otherwise, I'd go with 24p.

In an effort to look "filmic," a lot of documentaries are shot in 24p. So 24p may be something festivals and distributors see as a plus. I just watched four documentaries this past week and got to ask the filmmakers questions. I stopped asking the 60i/24p question, b/c it became pretty obvious 24p would be the answer. And these films ran the gamut from 16 mins arthouse picture to Academy Award nomiated feature. Surprisingly, two them had quite a bit of movement.

One real adavantage of 24p that often fails to get mentioned in these types of discussions is that it requires less light than 60i. And in adequate light, it allows you to open the lens wider to create shallower DoF.

HTH.

24p has the advantage it can be ported to pal, with 4% speed change.

But why not shoot both? It's going to be broadcast at 60i anyway. Just add 3:2 pulldown flags to the 24p and put it inside a 60i stream along with native 60i. The TV set will remove the pulldown and play it back as 24 fps progressive or at 72 hz, 120 hz etc. It's going to look the same. A good display will play it back without artifacts, and you aren't in control of the viewer's display type anyway. And if you were to insist on 24p progressive encoding without pulldown flags, the broadcaster is going to add them for you, unless you are distributing the collaboration on Blu-ray or DVD.

I don't see any reason for not shooting in the format you like, even mixing them inside the same program.

I was wondering about the interpolation issue - I wasn't aware that any 120hz displays were actually interpolating additional frames. However I was in best buy recently and they were running a blu-ray demo on a 120hz tv with clips from a bunch of major feature films - it was one of the most shockingly bad things I've ever seen. 'Gone in 60 Seconds' (the nic cage version) is hardly a cinematic masterpiece, but it's amazing how much worse it looks shot on home video - which is exactly how it looked as what I can only assume is interpolated 120fps video. Add to that the occasional odd artifact on the edges of occluded objects during camera moves and it was truly bad. I was hoping it wasn't a function of the display and just an overzealous editor who ran everything through twixtor or something.

I'd recommend going with 24p - I've yet to see a situation where it produced worse images, pulldown or not, on a progressive display compared to interlace. It compresses significantly better for online delivery than 60i or even 30p - and the reality is anything you produce now should have online delivery as a big consideration. It's much better to work with in post if you're planning to do any kind of significant work in AE, etc. Shooting at 1/48th you also get more light... as others have noted though you need to be more careful about shooting it. Handheld is going to require some sort of stabilization/brace with small cameras and you need to keep pan/tilt speeds down unless you're following a moving subject.

I think Steve said he would be shooting from a boat. I would think the boat motion as well as wave motion might make 24P a less than ideal choice. Even if the distant waves were out of focus there would be lots of wave motion near the swimmers which should be in sharp focus.

Maybe it depends on the size of the boat - the QM 2 would probably be a pretty smooth platform but a smallish boat in any kind of choppy conditions would be bouncing around a fair bit.

Am I missing something? Comments?

To my knowledge all the 120HZ displays interpolate the extra frames. Certainly that is the marketing pitch from Samsung, Sony and LG. IT is an attempt at smoothing out the natural judder of an LCD display whether it is showing 24p or not. For 24p, I think it is called cinema mode or something the displays should sense the 24p input and repeat frames rather than interpolate to emulate a film projector. Not sure how good they are that either!!!. To me the smoothest images at the moment are from 720P60. They don't mess with the display cadence and have good motion without judder of 24p. Most computer LCD displays also refresh at 60HZ so 30P would be a better choice for internet distribution sometimes 15fps so neither of these matches 24p very well either. 24fps is a film legacy unless one wants to make a film master I see little point in shooting 24p. If you must shoot progressive shoot 30p or 60p they will give better motion and save the poor viewer from a juddering mess when shown on a video display.

Ron Evans

I've watched many, many hours of 24 frame originated material (films, television shows, my own & other's 24p videos) on a wide range of video displays, from CRT to LCD, Plasma and LCD & DLP projection and I have yet to see anything I'd call a 'juddering mess' short of the occasional hand-held home video - certainly nothing that was shot professionally. When you watch tv or a feature film on an LCD or plasma (not a new 120hz model) do you see a 'juddering mess'?

No Reservations with Bourdain is shot in HDV 24P; look good to my eyes on TV as on my MBpro when downloadded from Itunes.

Unfortunately I feel a lot of what I see on my Panasonic 1080p Plasma over cable is a mess. Normal HD TV which is 1080i or 720p is smooth some programs have considerable judder including most films. Compared to my own HDV or AVCHD played back on the same plasma a lot of cable has a considerable amount of judder. I find my PS3 upconvert to 1080p30 is also unacceptable. I find it better to use my old Sony DVD player and let the Panasonic convert to progressive at the display. I may be very sensitive to judder but thats the way it is. I have a few Bluray discs and find them to have considerable backround judder too. They are concert discs likely shot in 30p. I have yet to see them from another player. The PS3 will play back 1080i AVCHD just fine but seems to insist on converting others to 30p. I guess it is just my old eyes but I dislike the judder in film I took in the early 60's and have tried to remove this defect ( in my eyes) ever since. For me its 60i or 60p or faster. My eyes don't work at 24p they require refresh rates in access of 50hz to give smooth motion, 60hz is better. Repeating the same frame doesn't remove the judder just exceeds the flicker rate for ones eyes. Shooting video at less than this rate means there are missing frames of information. One can just ignore them and judder from one frame to the next, one can shoot at the higher frame rate of the display or can use technology to fill in the missing pieces( attempted by the 120hz displays) . My preference would be to match the frame rate of the display refreshing at 60hz or greater.
Shooting at 24p doesn't match any video display. It is a valid approach to get to film. If you shoot purely for video then today the best is 60i( or 50i in PAL). To get better progressive motion shoot HD 720p60.

Ron Evans

Steve Mullen has a post on this topic in the AVCHD section.
http://www.dvinfo.net/conf/showthread.php?t=124261 There have been long discussions in this section too.

Ron Evans

Ron, I'm familiar with what judder is and I can see it in films all the time, more so on the big screen but on the tv as well - it's just that I don't find it particularly distracting or bothersome and in general I prefer the look for dramatic work. I was just curious if you see it all the time in 24fps footage or only in conjunction with particular 24p cameras - which are two different issues I've seen discussed on the forums here.

24fps originally was a compromise between cost and audience perception - it was determined to be the threshold at which most of the audience would still see relatively smooth, continuous motion. That means, however, that there is always going to be a small part of the audience for whom the threshold is too low - and you're clearly in that portion of the audience. Knowing this makes shooting 60i or 60p a clear choice for you, but that doesn't make it the best choice for everyone else - and saying choosing 24p will result in a 'juddering mess' simply isn't true for most of the audience.

For most people the choice really comes down to the nature of your subject - and getting back to the original question it's not the case that you have to choose one or the other exclusively. For something like a sports doc it would probably work well to shoot the action footage 60i (or 60p if your camera supports it) and interviews 24p and edit everything in a 60i timeline - I'd just say that if you're going to do this you should be consistent in which format is used in which situation.

It is my understanding that 24fps was a compromise for acceptable sound reproduction and cost of film stock needed for distribution. Prior to sound, film was shot at a number frame rates some quite low and all experienced judder whether the audience saw it or not. Most people see judder when it is explained and pointed out to them. As you say it is in all films. Any pan will surely show judder however slow. 24fps just isn't fast enough. I accept that some people say they like it for artistic effect. I am sure the real reason is to make a film at film speed even if it is never transfered to film and unfortunately is shot as if it is video with bad judder. This also applies to bad TV productions shot at 24p. The skill level needed to shoot 24p is high and unfortunately not achieved by a large number of users including producers for network television. In my mind if the background judders it has been shot badly, that happens a lot on network TV. It means the camera angle was wrong, the depth of field too large etc etc. generally the cameraperson didn't really understand what they were doing in 24p. I like the film camera approach used to mitigate the slow frame rate. Closeups, shallow depth of field, etc etc it is just that I feel the need for a slow frame rate with judder is just not needed with todays technology and economics. Remember it was economics that created the speed not artistic needs or technology. It remained also because of economics( all those theatres with projectors ). In fact it is still those theatres that trap film to this speed, unnecessary either by general economics or current technology. One doesn't have to give up all the other film shooting characteristics that generate the film mood to shoot at a high frame rate. It just means the judder will go. Even film festivals are starting to project with video projectors so even that is starting to make 24p likely unnecessary. High definition places extra demands on focus and motion because they stand out more. Badly shot high definition is really bad!!!!
As to the original question documentaries to me are a means of placing the audience in a position to gain knowledge of the topic. The closest to the actual image one can achieve is the correct choice for documentaries in my mind. That would be 60i or 60 p with todays technology. For a drama the producer of the story has their choice and if they like the film look with or without judder is their choice

Ron Evans

This thread is a month old, so any info probably won't help the OP. However, I work with people in the television and film industry every day, and we often have discussions on what frame rates people prefer to see. The general agreement is that video or film at 24 frames per second is perceived as a more expensive look than video at 60 frames or 60 fields per second. The reason is that watching a motion picture at 24 frames per second is like looking at a series of photographs at 24 frames per second. Photographs look as though they could be from another time and another place, even when they are taken recently. There is a separation between the person viewing the photo and what's on the photo. Projecting a sequence of 24 photos per second still gives the audience the feeling that what they are watching could have happened at another time and another place, and it doesn't have a "live" feel to it, so the audience feels more separated from what is happening on the screen. Video at 60 fields per second on the other hand does look "live," and the audience feels like it's "live" even if it's on tape. The Tonight Show for example looks "live" even though it's taped in the afternoon. Even film projected at 60 frames per second, such as the Showscan format, starts to have more of a live feel as it takes on more of a "video" look. A good example of film vs video frame rates, is that when you see a film of John F. Kennedy making a speech, it looks like it happened a long time ago, but when you see a video tape recording of the same speech, it looks like it could be happening right now. Our newscasts and live sports have always had a live video look, and that look is perceived as being a "cheaper" look than motion pictures. Also, it is the 24 frame per second cadence that creates the "film look" far more than any other factors. Some will argue that it is the lighting or the color correction, but actually it is just the cadence that makes the difference. A good example is that even if you watch an old film on an old TV with horrible color and noise, you still know right away that it is a film, and not live video, and of course watching a HD movie today is even more similar to seeing it in a theater. So for a more expensive look, shoot 24p.

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I can see that if the industry feel 24p gives an expensive "look" it will be used!!! I agree with the comments on 24fps film looking as if it occurred at another time or old. Gives the image an unreal effect and perfect for fiction. Film viewed in a cinema with good projector will give this impression. Unfortunately the same film translated badly for television and viewed on a low cost LCD panel will not be very good and certainly will look more "old" than "expensive" !!! This is the issue that is important to me. Film was designed as a system 60i was designed as a system unfortunately parts of the system are now being translated with newer technology that doesn't quite match the original system specs. Steve has a few good posts in the AVCHD section. To view 24fps on a flat panel display it should really emulate the film projector and as such should refresh at 72hz with no interpolation (3:3) with a source that is true 24fps under these circumstances it should produce a good image close to the cinema experience. This is not the normal viewers display chain and performance will vary wildly depending on source and display type. Unfortunaley only outcome for the normal viewer is judder from various causes ( see Steve's post). So the expensive looking film in the cinema has now been compromised by the reality of the consumers display chain technology. Flat panel displays have a particular problem so the manufacturers are thus trying to solve this perceived problem with their displays and as such are introducing interpolation and higher frame rates to "smooth out " the problems!! Net result the expensive film look turns into video for those fortunate enough to buy a new high tech display!!!
Interlaced sources are not immune either as a lot of displays turn a 60i source into 30p also inducing judder from what was viewed on a CRT as nice smooth motion!!! This is a case where interpolation is needed to emulate the picture the viewer was used to on a CRT. NTSC is 60 fields a second NOT 30fps. The cameras shoot at 60 fps it is just that only half the vertical resolution is shown at a time( again like film at 24fps an economic decision lowering the transmission costs) . The system design included a display with phosphors that decayed in a way that our eyes and brain filled in the missing lines( if we were far enough away from the screen to not actually SEE the lines).
Consumers wanted a bigger display with less bulk hence flat panel displays that by their nature were progressive. Unfortunately these were not designed as a system. One could say they were designed with little regard for either film or 60i video, the only sources available to them!!! They corrupt the picture from both sources!! A display with source sensing, 72hz refresh for film and 60i interpolated to 60p for interlace video would solve the problem but I don't expect we will get this!!

Ron Evans

I certainly agree that 60 Frames per second is "better" technology, but the 24 frame film cadence is still a classier look. The closer something looks to live, the cheaper the feel. That's why even a low budget film with a bad transfer still feels more expensive than a soap opera shot with 60i video cameras. The Young and the Restless is 1080i, and it looks and feels totally different than CSI or Two and a Half Men which are 24p. And most film purests hate the new technology in displays that adds extra frames, because it cheapens the look of the film.

Thats a matter of opinion and depends on the subject matter. If the video is of a live production in a theatre then I would like it to feel as close as possible to sitting in the audience or looking through a window on the stage. High frame rate, high resolution and immersive surround sound. I have no problem with using 24p cadence where the subject is fiction and the whole point is illusion. The issue I have is the "one size fits all" mantra of the 24p supporters. Using 24p for a training film or documentary where detail and high frame rate would be important to view things as they are in real life for instance. Using 24p cadence in these instances has the opposite effect than desired--infers that the subject matter is NOT real. Raising doubts as to the credibility of the program. So the use of "cheap" or "expensive" really relates to what one is trying to achieve.
The other point I was trying to make was that the current flat panel displays are not very kind to either 24p or 60i leading to the possibility that neither is actually displayed as intended. The near future may make this even worse not better.

Ron Evans

I like the "live" look for certain situations. News and sports should look as live as possible. The NFL looks great live with 60i or 60p frame rates, and the upcoming 3D technology will allow two separate alternating 60p pictures in a 120 frames per second display--which makes for some very good flicker free 3D. Sony had a good demo at this years NAB. I also enjoy watching NFL Films versions of games after the fact, which again has a totally different look and feel than the live cameras.