In what frame-rate to shoot for final in multiple standards?

[Joshua_1]

I'm about to shoot a documentary.
It will be presented to HD TV stations in both Europe and USA and also to film festivals.

AFAIK, conversion from any standard to any other one can be made in post production. Thus, the end movie will be copied in few formats (1080p30, 1080p25, 1080p24). My question is what's the best frame rate to shoot in, so that format conversions will degrade the least the technical quality?

 

[ChimpPhobiaFilms]

I'm about to shoot a documentary.
It will be presented to HD TV stations in both Europe and USA and also to film festivals.

AFAIK, conversion from any standard to any other one can be made in post production. Thus, the end movie will be copied in few formats (1080p30, 1080p25, 1080p24). My question is what's the best frame rate to shoot in, so that format conversions will degrade the least the technical quality?

What frame rate it will be broadcasted it.

1080p, 25fps?

Also, it's very hard to tell the difference between the 3. Most people can't tell the difference at all.

 

[Joshua_1]

Since it may be broadcasted in both Europe and the USA, it may be broadcasted in both 1080p30 and 1080p25.

My question wasn't about what people notice, or not. My intention is to present a copy of the proper format to each potential broadcaster/screener (if used the proper terms). I prefer to have control over the format conversion process and outcome, therefore I prefer to do the formats conversions locally.

My question is what frame-rate is it best to shoot in, having in mind that the final movie will be in all 3 formats? That is, shooting in what frame-rate will have the least degradation in technical quality after conversion to the 2 other standards?

 

[ItDonnedOnMe]

It's easy to convert between 24 & 25 with just a slight (and largely unnoticeable) speed up/down. It's not easy to convert between 24/25 and 30 - you either drop/double frames which makes motion jerky, or it takes a lot of processing to generate blended frames, which can introduce motion artifacts.

25p can be converted easily to 50i for broadcast, and 24 converts easily to 60i with a common 3:2 pulldown - I don't believe 30p is actually a broadcast standard , so it's more likely you'll be using 50/60i if you go to broadcast.

So I'd say choose between either 24 or 25 based on where you expect the greatest distribution - US or Europe - and then you've got a good basis to convert to pretty much any common delivery format you'll need without too much processing or impact on quality. EDIT - just saw in the other thread your primary audience is likely PAL so I'd start with 25p.

 

[taylp]

This knows what he is talking about.
Listen very carefully.

It's easy to convert between 24 & 25 with just a slight (and largely unnoticeable) speed up/down. It's not easy to convert between 24/25 and 30 - you either drop/double frames which makes motion jerky, or it takes a lot of processing to generate blended frames, which can introduce motion artifacts.

25p can be converted easily to 50i for broadcast, and 24 converts easily to 60i with a common 3:2 pulldown - I don't believe 30p is actually a broadcast standard , so it's more likely you'll be using 50/60i if you go to broadcast.

So I'd say choose between either 24 or 25 based on where you expect the greatest distribution - US or Europe - and then you've got a good basis to convert to pretty much any common delivery format you'll need without too much processing or impact on quality. EDIT - just saw in the other thread your primary audience is likely PAL so I'd start with 25p.

 

[ChimpPhobiaFilms]

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[AudioPostExpert]

What frame rate it will be broadcasted it. 1080p, 25fps?
Also, it's very hard to tell the difference between the 3. Most people can't tell the difference at all.

This knows what he is talking about. Listen very carefully.

Please do not listen very carefully, he does not appear to know what he is talking about!

There seems to be a lot of confusion/ignorance here about frame rates/field rates, when they are used and what they mean, regardless of what they are often inaccurately called. It's got nothing whatsoever to do with whether people can tell the difference between the formats on a computer screen. The OP has this is for HDTV broadcast and film festivals and in this case people will most definitely be able to tell the difference. This is because the difference is between people seeing your documentary broadcast/screened and your documentary not being broadcast/screened and therefore people not seeing it!

It's entirely possible that NONE of the formats listed in the original post is actually useable for what the OP intends! For HDTV broadcast in Europe the HDTV broadcast standard is 1080i50 (not 1080p25), which is 50 interlaced fields per second. For HDTV broadcast in the USA the standard is usually called 1080i60. However, 1080i60 in the USA is not 60 interlaced fields per second (as the name implies and as it is in Japan) but 59.94 fields per second, a small but vital difference! The US HD broadcast standard should really be called 1080i59.94!

Film festival screening is variable from festival to festival depending on which exhibition format/s the festival supports. In the case of DCP, the most widely compatible international format is a resolution of 2K and a frame rate of 24fps, that's a true 24 frames per second by the way and not the USA 1080p24 frame rate of 23.976. However, the updated DCP spec supports a wide array of frame rates (including 23.976, 25 and 24) and resolutions from 1080p up to 4k. In practice, 1080p25 and 1080p30 are rarely/never used as a distribution format and 1080p24 usually means 1080p23.976 and is only used commercially for BluRay distribution (and is therefore suitable for those film festivals which allow exhibition copies on BluRay).

A good commercial post production facility should know all of these different frame rates and resolutions and the implications of using and converting between them. If you are going to try and do it yourself, this area can be a minefield if you are not well versed in the different international broadcast and distribution formats (as my previous two paragraphs demonstrate!). For example, the difference between true 24fps and 24p (which usually means 23.976fps) could result in your audio drifting out of sync with your picture by about 6-7 frames per 5 mins!

Sorry, I cannot give you definitive advice on what your acquisition format should be. As a general rule, you would want to shoot at the highest resolution you might need, which in the case of cinema screening could be 2K 24fps but I don't believe most DSLR cameras support either 2K or 24fps! I would advise that you get hold of the specs of the broadcasters and of the film festivals you wish to enter and then get some advice from a professional DP or commercial post production facility with experience in creating commercial products destined for both cinema screening and HDTV broadcast in Europe and the USA. Far easier would be to simplify your intended final output (a local HDTV broadcaster OR a local film festival for example) and shoot/edit/output in that specific format.

G

 

[ChimpPhobiaFilms]

Please do not listen very carefully, he does not appear to know what he is talking about!

Fair enough. I am not very knowledgeable about frame rates for broadcasts, and which frame rate to choose for a conversion.

Also, he was quoting IDOM, not me...

 

[jax_rox]

Has it been purchased in Europe?
Has it been purchased in the USA?

Or, do you hope that entering it into film festivals will elicit a purchase for those territories?

If the former, get the post house to do the conversions, and talk to the television networks about what they want - they'll have some pretty strict guidelines in place.

If the latter, shoot what you need to get a good image (let's say 1080, 2k or 4k @ 24p) and deal with the conversion issues if it gets purchased

 

[Joshua_1]

Thank you all.

I'll consult a local post production studio.

 

[ItDonnedOnMe]

Please do not listen very carefully, he does not appear to know what he is talking about!

On the contrary, I actually do know exactly what I'm talking about. You've succeeded in making the issue more complicated than it needs to be at this point, which is exactly what I was trying to avoid by using 24/25/30p as shorthand for the actual frame rates in camera - just as the camera manufacturers often do.

In his other thread he mentions he's shooting on a 7D. In NTSC the frame rates he has to choose from in the menu are 24p or 30p, in PAL 25p or 30p. It really doesn't matter at this point that those actually represent 23.976/25/29.97.

The conversion from 30p to 24p, 25p, or 50i is messy, and likely to have a noticeable visual impact - so that makes it a poor choice, especially if his most likely market is European broadcast.

So that leaves 24 or 25. Since his primary market is PAL, 25p is the correct choice.

The details of converting to the precise frame rate that it ends up in for the deliverable will be the responsibility of whoever is doing that conversion - at this preliminary stage I'm assuming it probably won't be him. If it is he'll have to learn about the correct precise frame rates at that time, but it has no impact on which frame rate he needs to choose in his camera now.

 

[Joshua_1]

Thank you.

…
In his other thread he mentions he's shooting on a 7D.

That was a preliminary thought.
I'll rent a pro cine camera. The 7D will shoot simultaneously for possible inter-cats, from somewhat different angle and perspective.

…
The conversion from 30p to 24p, 25p, or 50i is messy, and likely to have a noticeable visual impact - so that makes it a poor choice, especially if his most likely market is European broadcast.

So that leaves 24 or 25. Since his primary market is PAL, 25p is the correct choice.

It seems that shooting in 25p is the preferred option. However I'll consult a local post production studio to be sure.

The details of converting to the precise frame rate that it ends up in for the deliverable will be the responsibility of whoever is doing that conversion - at this preliminary stage I'm assuming it probably won't be him.
…

Indeed. I cannot do the post production on my own, not for the intended distribution.

 

[AudioPostExpert]

You've succeeded in making the issue more complicated than it needs to be at this point, which is exactly what I was trying to avoid by using 24/25/30p as shorthand for the actual frame rates in camera ...
In his other thread he mentions he's shooting on a 7D. In NTSC the frame rates he has to choose from in the menu are 24p or 30p, in PAL 25p or 30p. It really doesn't matter at this point that those actually represent 23.976/25/29.97.

I have not made the issue more complicated, the issue is complicated on it's own without my help, explaining the truth of the matter (regardless of complexity) is preferable in my opinion to simplifying it to the point that it's inaccurate.

As you've apparently read the other related threads, you are aware that the OP is hoping for a two stage process: A simple documentary for local film festivals and to use to pitch for sponsors for the second stage which is a docu-drama and to bring the entire project up to HDTV broadcast standards (local and international). For the first stage the OP has a very limited budget and will likely have to do most of it himself.

The trend with many/most indietalkers and inexperienced indie filmmakers in general seems to be to rush out and make the film and then figure out how to make it suitable for various film festivals and/or distribution channels. This is the complete opposite of how the industry approaches filmmaking because the different distribution channels and festivals have different specifications/requirements which necessitate different budgetary considerations/priorities. The OP is being wise in my opinion in asking these questions before starting. The information I have given was designed to allow the OP to make an informed decision based on his priorities and circumstances, rather than giving a simple answer which could cause the OP serious problems. For example, if the priority for stage one is a local film festival/s the OP needs to find out what the exhibition format is for those festivals and shoot/edit in that format and leave the conversion to HDTV format to the Pros when/if he has the funding for stage two. Maybe the local festival/s he is interested in require BluRay for exhibition or maybe DCP, in either of these cases 25p might be the poorest choice for acquisition. If the exhibition format is DCP the OP will need to prioritize his budget for the costs of making a DCP and be aware of the difference between 24p (video speed) and 24fps (film speed), otherwise he's going to run into problems, potentially catastrophic problems as his initial budget is very limited. Or, maybe the OP's priority is for local HDTV broadcast for stage one, in which case 25p would likely be the best choice. In either case, the OP needs to research either the local film festival/s or the local HDTV station to find out for sure what format they need/require (resolution, frame rate, audio specs, etc.) and then go to a local post house (audio and visual) and ask their advice on which acquisition format would be the easiest for them to deal with, baring in mind the intended stages and eventual screening/broadcast requirements.

G

 

[David.rhsc]

I just shot a reality show intended for both US an International distribution. Our post team wanted to acquire in 1080p30 to ease conversion for the most markets, so that's what we did.

Take that for what it is worth.

 

[Joshua_1]

Thank you, all.

 

[ItDonnedOnMe]

Look, it's really simple - this is purely a question about ease of conversion. If you start with either 24p or 25p it's easy to end up with any of the following common frame rates with minimal impact on image quality:

23.976p
24p
25p
60i
50i

If you start with 30p its easy to end up with:

30p
29.97p
60i

That's it. Anything outside of those will require a much more complicated conversion process (involving dropping, blending, or morphing frames) which will negatively affect your image quality.

So look at those two lists and choose the origination format that covers the most potential frame rates you'll need to deliver on.

The only caveat I would add is to beware of cameras that say 24p but wrap it in an 60i stream (the 7D doesn't do this). If the camera can't produce a true progressive file then it's probably not worth the trouble it will cause you later.

Maybe the local festival/s he is interested in require BluRay for exhibition or maybe DCP, in either of these cases 25p might be the poorest choice for acquisition.

At this point you're crossing over from merely making things more complicated to actively spreading FUD. The DCP standard (as well as Blu-ray) accepts both true 24p and 25p; if the festival specifies one or the other it's a simple matter of a 4% speed change to convert between the two - a standard conversion that is commonly performed every day as projects are converted between NTSC & PAL for broadcast, and one that has no negative impact on the visual quality of your film.

I just shot a reality show intended for both US an International distribution. Our post team wanted to acquire in 1080p30 to ease conversion for the most markets, so that's what we did.

That's an odd choice. If you look at the lists above you can see 30p doesn't convert cleanly to anything beyond NTSC standards. It's not that you can't do the conversion - it's just that you'll almost always lose something in the process.

There are certainly workflow & equipment issues that might make 30p their preferred choice, but then the choice is being made for reasons other than image quality. Maybe it had to do with the specific cameras you were shooting on? i.e. if the choice is between 24p in 60i and 30p in 60i, I could see them wanting to avoid the need to do a reverse 3:2 pulldown on all of the footage you acquire before they can start editing. Or between 60i and 30p they might just prefer not to deal with interlacing. For NTSC broadcast reality is also more commonly shot at 30p for the "real" look, so they may be simply prioritizing that look for the primary market at the expense of some image degradation when it goes to PAL regions.

 

[David.rhsc]

*shrug*

Frame rate conversion isn't really my forte, but I know what they wanted to acquire with, and that's what they got. I don't know if it was so they could distribute in 25, but I do know that this thread is the first time I've seen 24ntsc as a suggested frame rate for later distributing in 25pal. But again, not something I've spent a lot of energy thinking about, so not really valuable information outside the recent practical application as an example.

 

[ItDonnedOnMe]

Well, the 24->25 conversion is the way theatrical films have been converted for PAL broadcast for decades. Shoot film at 24fps, speed up to 25fps, then split each frame to create a 50i broadcast signal. It produces a clean conversion with no image degradation (other than slightly faster playback, which most people won't notice).

With 30p there's no clean way to get to 25 (or 24 for that matter). You can drop every 6th frame, but that adds a stutter to the motion which doesn't look good. A slightly better option is to blend every 5th & 6th frame together, but that still is visible as an odd rhythmic flicker in the picture. Nowadays the best option is to run it through frame-rate conversion software, which actually analyzes the motion of the pixels and generates a completely new set of frames which are all warped slightly to create evenly spaced motion steps. There's still a couple problems with that process - first off, it can get confused by fast motion or occlusion, so you can get odd warping effects in parts of the image. The second problem is that the process of analyzing the motion of every single pixel is incredibly slow - and generally the better quality the result, the longer it's going to take to render.

So personally I would never choose 30 as a starting point for something expecting either PAL or theatrical (24fps) distribution - but again that's assuming you are starting from a blank-slate as far as equipment and workflow is concerned.

 

[AudioPostExpert]

At this point you're crossing over from merely making things more complicated to actively spreading FUD. The DCP standard (as well as Blu-ray) accepts both true 24p and 25p; if the festival specifies one or the other it's a simple matter of a 4% speed change to convert between the two - a standard conversion that is commonly performed every day as projects are converted between NTSC & PAL for broadcast, and one that has no negative impact on the visual quality of your film.

Here we go again, making incorrect statements and accusations based purely on image quality. Being a filmmaker means knowing about sound and not just about images and image quality. If all you know or care about are images and image quality you are a photographer not a film maker and certainly not a filmmaker seriously looking for distribution or broadcast as is the OP, as there isn't much demand for silent documentaries these days!

Speeding up your movie by 4% might not affect your images too much but it will affect the sync with your audio and just sample rate converting the sound to speed it up by 4% to match the images will change the pitch of any music, effects and the timbre of the speaking voices, so you have to re-sample and pitch shift the audio which can be tricky to do without artifacts.

And yes, the current DCP standard does allow a variety of frame rates but prior to the current variety of allowable frame rates DCP could only be true 24fps. To enable the digital projectors to work with different frame rates requires an upgrade and there are many digital cinemas around the world which have not upgraded their systems and can only screen 24fps DCPs. For this reason, although the standard technically allows for other frame rates, it is highly recommended to only use 24fps for DCP to ensure compatibility and why all commercial theatrical films are still released at 24fps. This is another reason why the OP needs to do some research about the film festivals he wishes to enter as it maybe that the cinemas where the festival/s screen have updated their systems, in which case he maybe able to use 25p for the DCP and 50i for local broadcast. If they haven't updated their systems then 24fps could be a mandatory requirement and 25p may not be the best choice for acquisition, as I stated before.

G

 

[ItDonnedOnMe]

Speeding up your movie by 4% might not affect your images too much but it will affect the sync with your audio and just sample rate converting the sound to speed it up by 4% to match the images will change the pitch of any music, effects and the timbre of the speaking voices, so you have to re-sample and pitch shift the audio which can be tricky to do without artifacts.

And yet this exact process is done for hundreds (actually probably thousands) of films a year that are shot at 24p and broadcast on PAL networks or released on PAL DVDs. Or, the reverse, for PAL originated shows that are broadcast in NTSC countries. It's not like I'm suggesting some obscure trick to make things work across different standards - this is the way it's done, and it's the way it's been done for decades.

If they haven't updated their systems then 24fps could be a mandatory requirement and 25p may not be the best choice for acquisition, as I stated before.

Actually you said it might be the poorest choice, which is what I was reacting too, and which is clearly false. 60i would probably be the worst choice, followed closely by 30p, and then maybe 50i. Obviously 24p would be the best choice if you know that that's what you're most likely to need. But if PAL broadcast is equally likely to a theatrical release than you're pretty safe with either 24 or 25 as you're going to have to convert one way or the other.