digital movie frame rates

[smthopr]

24 FPS
Motion pictures shot on film do so at 24 FPS (frames per second). Since the days of the silent movies this has become the standard frame rate for movies. Video has 30 FPS as its standard rate. This produces a different "look" than film, which appears a bit more blurry because of its slower shutter speed – shot at 1/60th of a second per frame rather than 1/48th of a second.

Many videographers trying to make their videos look like they were shot on film prefer cameras which shoot at 24 FPS, and their holy grail is known as 24P, of 24 FPS progressive.

Frankly, I find this similar to the affectation that some digital still photographers have for making their images a bit grainy so that they look "film-like". No thanks.

Thanks Micheal for your interesting article on digital movies.

I just thought I'd make a comment about the advantage of shooting at 24fps.

While I agree that 30p looks better than 24p (more data per second), 24fps has four advantages:

1. Nicely converts to 30P or 60i formats by adding 3:2 pulldown (duplicate frames added) that looks just like hollywood movies transfered to video that we're used to seeing.

2. Easily converts to 25fps for European TV HD formats by speeding up the movie a tiny bit.

3. Is perfect for printing to film for theatrical distribution at 24fps

4. Plays back well for web viewing with lower bandwidth requirements than 30fps.


If you shoot at 30fps (30p) and need to convert to 24fps, dropping the frames will make for very jerky, unnatural looking motion.  If you shoot at 25p, it does not convert as well to 30fps for US tv.

So, 24fps (24P) is kind of a universal mastering frame rate for world wide distribution in multiple formats.

[michael]

This is all very true.

But for the vast majority of amateurs who will never transfer to film for theatrical release, and who won't be having their work broadcast on European TV (or elsewhere for that matter), I feel that the advantages in terms of image quality of 30fps outweigh the disadvantages.

Having said that, if I thought that anything I was shooting had even the vaguest chance of release to film, I'd shoot 24 FPS.

And, since we are now in a transition period when theatrical release is (slowly) changing to digital presentation in theaters rather than using film, even that paradigm is changing.

Michael

[Graeme Nattress]

With frame rates, there's always a number of different benefits in terms of image quality, temporal portrayal of motion, compressability, and international conversion. There's no one right answer, but there's often a wrong answer :-)

24p - (usually 23.976fps in NTSC countries). The film rate. Lower bandwidth requirements. Converts to 60i via 3:2 pulldown, converts to 25fps via speeding up 4%. Great for low bandwidth applications like web, and can also make for a 24p DVD with better compression. However, often 24p is contained in the interlaced 60i format via 3:2 pulldown, or recorded with an "advanced pulldown" that should be removed before post production work. Removing pulldown is the biggest pain, and workflows need to be carefully thought out.

25p - (sometimes a PAL country film rate) Converts to and from the film rate of 24fps via 4% speedup or slowdown. Converts to the PAL video rate of 50i without any conversion at all. Can be converted to NTSC via a modified pulldown, or conversion to 24p then traditional pulldown. Great for low bandwidth uses as 24p. No pulldown issues for editing makes post production simpler if you're in a PAL country.

30p - (base progressive NTSC rate) Still retains some of the film feel as it's a relatively slow rate. As 25p no pulldown issues. Works good for web or low bandwidth applications, or NTSC DVD. Tricky to convert well to 24p or 25p, makes it the least suitable format for international work or potential to go to film or integrate with a project at film rates. Easier temporal presentation making control of panning speeds a little less critical than with 24p or 25p.

Shooting interlaced, 50i or 60i has really none of the above benefits of the above formats. They do however look very smooth and it's hard to pan so fast that the image stutters. They're tricky to convert to other rates, although through deinterlacing 50i goes well to 25p, and via slowdown to 24p and 60i goes to 30p well, and with a little magic, 60i goes to 24p quite well indeed.

Graeme

[lticheli]

Which is better, 24 fps or 30 fps?

Contrary to what one might expect from simply reading the numbers, 24 fps is much better for dramatic visual story telling than 30 fps.

Why? I'll tell you.

There is a subtle but very distinguishable difference in the smoothness of the action between a 1/48 second and 1/60 second exposures. The motion blur in the longer exposure is simply more pleasing. The action is smoother and more natural looking.

Both exposure settings are dependent on using either a mechanical or electronic shutter of 180°. This produces a blanking period so that only half the action is covered. Why? Because film cameras required the blanking period to unlock the gate, move the film to the next frame, and then lock the gate again before the exposure.

Filmless capture requires no blanking period, so why retain this? Because the brain fills in the missing visual information and this increased demand/activity creates more involvement and increased viewing pleasure.

These factors may sound paradoxical, especially to stills photographers who expect sharper to always equal better, but simply viewing a motion picture vs. video shot at 30 fps immediately reveals that the "old fashioned" 24 fps with a 180° shutter is much more enjoyable to view.

30 fps material tends to look cold and lifeless, very "video." That's not a complement.

Certainly there are subjects where higher, and often much higher, frames rates are more appropriate, sports for example, but for the narrative, dramatic film, 24 fps rules.

Good shooting and best regards,

Leo

[Graeme Nattress]

Great to see you here Leo!

I personally I don't see "too" much difference between 24p, 25p and 30p (keeping them all at 180 degree shutter). What you do see is the 3:2 pulldown on 24p that you won't see on 30p, but I don't really think that's visually benefiting the image. Of course, go to 50p or 60p and the difference is quite obvious, (or traditional 50i or 60i for that matter). 30p does look different to 24p for sure, though, but it's not the order of magnitude difference going to 60p makes.

Shutter does make a difference as you go from  the traditional film shutter which is 180 degrees through to the video traditional fully open shutter (360 degree), again it's an order of magnitude difference.

The fps aesthestic of 24p is however, very cultural, and depends upon where in the world you grew up.

Graeme

[michael]

Here's an interesting thought experiment.

If we had not evolved out of the film world, do you think that we would have invented 24P, and would we think that I looked "better" than 30P, or simply blurrier?

In other words, is the appeal of 24 fps just a cultural artifact or would we have invented it even if film had never existed?

Michael

[lticheli]

Here's an interesting thought experiment.

If we had not evolved out of the film world, do you think that we would have invented 24P, and would we think that I looked "better" than 30P, or simply blurrier?

In other words, is the appeal of 24 fps just a cultural artifact or would we have invented it even if film had never existed?

Michael
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Hi Michael,

This argument is not new; it's been widely asserted that 24 fps/180° shutter is a standard only because it was the lowest non-flickering frame rate and therefore chosen because it was the cheapest.

Yes, it's true; that's how the standard came to be. Well, the advent of sound did bring us to this. This does not, however diminish the effectiveness of the standard! We've had plenty of opportunities to change the rate and there are a plethora of programs shot at 30 fps (60i).

While programs shot at 24 fps tent to have been made with higher production values, the fact remains; programs shot at 30 fps tend to have a "video" look that is far less appealing. Frankly, they look bad.

What about even higher frame rates for dramas? This has been tried as well, and although there were many factors contributing to it's demise, Showscan, a 60 fps attempt, was a failure. To be sure, the Showscan proponents claim audiences preferred the 60 fps material, but this is disputed.

More realism equals less magic. That's why we enjoy a good book; the brain is filling in what's not on the page.

Higher frame rates may be just the ticket for certain types of entertainment; hyper-realistic thrill rides, games, etc., but for the drama, for dialog, it erases the magic.

As we evolve to non-mechanical display methods, we may well see dynamically changing frame rates within a single program. Now that's something to think about...

To your question, if we had not chosen 24 fps out of economic necessity, would we have settled on it as the universal standard? I like to think we would have, just as we're finally moving away from the horrible plague of interlaced television.

One thing is certain, if you do your job artfully and shoot at 24 fps, you will receive applause.

Good shooting and best regards,

Leo

[michael]

Leo,

Thanks for the thoughtful response.

I'm leaving for Botswana next Monday and will be doing a video project with a Sony EX-1 as well as doing my stills work. I'll be shooting 1080P, but am torn between 24P and 30P.

Food for thought.

Michael

[lticheli]

Leo,

Thanks for the thoughtful response.

I'm leaving for Botswana next Monday and will be doing a video project with a Sony EX-1 as well as doing my stills work. I'll be shooting 1080P, but am torn between 24P and 30P.

Food for thought.

Michael
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Hi Michael,

Sounds like a terrific job; congratulations!

On the choice of frame rates, I suggest you shoot some test footage as similar as possible to what you expect to find in Botswana. View the clips and choose whichever pleases you.

Remember however that if you shoot 30p, your ability to go to PAL 25 fps is sure to produce disappointing results. With 24 fps it's a snap.

Good shooting and best regards,

Leo

[timescapes]

Graeme, I didn't know you posted here!

As a timelapse photographer, I obviously have my choice of FPS when I import an image sequence into After Effects or an NLE's timeline.  I always use 24p.  It's the beautiful, dreamy moving image framerate we are used to from movies, high-end music videos, etc.  Certainly higher FPS is more realistic, but IMO that is good mainly for sports, news gathering, etc.

[smthopr]

Leo,

Since we're shooting digital, why not shoot 30fps with a 1/48th sec exposure for each frame.  You'll have the motion blur of 24fps movies, with the added data/sec of 30fps.

Just for added discussion, I have a director whom I shoot for who's always asking about digital: But how do we get it to look like film?"

This question drives me crazy, when we don't have the budget to shoot 35mm!

That said, as I've gotten used to shooting digital (and viewing other's films digitally) I've come to really like the look of well shot digital movies.  When I then see a 35mm print, I feel like wiping the schmutz off the screen.  To me, a good digital projection looks much more pleasing than a shaky 35mm film print at the multiplex.

Michael, as to your trip to Africa, you might choose 24fps if you think you might be making a dvd or blue-ray disc for Europeans to play on their tv's instead of a computer.  Bon voyage!

[lticheli]

Leo,

Since we're shooting digital, why not shoot 30fps with a 1/48th sec exposure for each frame.  You'll have the motion blur of 24fps movies, with the added data/sec of 30fps.

Just for added discussion, I have a director whom I shoot for who's always asking about digital: But how do we get it to look like film?"

This question drives me crazy, when we don't have the budget to shoot 35mm!

That said, as I've gotten used to shooting digital (and viewing other's films digitally) I've come to really like the look of well shot digital movies.  When I then see a 35mm print, I feel like wiping the schmutz off the screen.  To me, a good digital projection looks much more pleasing than a shaky 35mm film print at the multiplex.

Michael, as to your trip to Africa, you might choose 24fps if you think you might be making a dvd or blue-ray disc for Europeans to play on their tv's instead of a computer.  Bon voyage!
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Hi Bruce,

If you alter the electronic shutter to 1/48 second, you change the blanking period duration and you're back with a video looking result. Perhaps you will like it, but most don't. You're still left with a master than is not acceptable for conversion to 25p.

I've found that when someone says they want the "film" look, they are requesting a beautiful look, the anthesis of a "live" video look, not grain.

I don't think we should confuse digital projection with a video look of acquisition at 30 fps. I personally favor digital projection because the "print" is much more likely to be free of damage and mechanical vagaries. Digital projection does not equal "video" look unless the material has the video look.

We now have the tools to achieve the 35MM film look with digital cameras; similar dynamic range, shallow depth of field, saturation, and resolution. It's not about grain; never has been.

Opinions vary, but 24 fps/180° shutter works for most dramas.

One of the great advantages of shooting digital is that you can test other rates and shutter angles and immediately view the results. Use whatever works for you.

Good shooting and best regards,

Leo

[Ray Maxwell]

Let's get a little historical perspective on this subject...

Back in 1986 at Expo 86 held in Vancouver B.C. several of the exhibits were presenting movies that used a new technology.  If my memory serves me correctly it was called Show Scan.  It used a higher frame rate than conventional film systems.  I don't remember the exact frame rate, but it was greater than the 24 fps double shuttered at 48 flashes per second.  Everyone raved about how sharp and clear the movie was and how smooth the action was.  In addition I talked with engineers who were very proud of how they had improved the film transfer so as to almost eliminate gate shake.  Everyone was very excited about this much improved technology.

Now you can shoot with the latest video equipment and you can then go out and buy filters that will put in gate shake, grain, blur, film transfer curves, and make it all look like you used equipment that is 100 years old.

Telling a good story when writing, through audio, or visuals, depends far more on having a good script than all of the technology combined.  Remember, the technologies are only tools to tell the story.

Michael knows that I love technology, but let's get a little perspective on this.

Ray Maxwell

[Graeme Nattress]

Unfortunately fps, and in particular 24fps is somewhat of a religious discussion. I don't see that 24fps has any particular magic, but I do see that different fps have a different feel. I'd dearly like to be able to choose the fps of a shot as I change aperture, focus and framing to evoke a certain feel, but we're not able to play back or edit such a movie at the moment.

[smthopr]

Let's get a little historical perspective on this subject...

Back in 1986 at Expo 86 held in Vancouver B.C. several of the exhibits were presenting movies that used a new technology.  If my memory serves me correctly it was called Show Scan.  It used a higher frame rate than conventional film systems.  I don't remember the exact frame rate, but it was greater than the 24 fps double shuttered at 48 flashes per second.  Everyone raved about how sharp and clear the movie was and how smooth the action was.  In addition I talked with engineers who were very proud of how they had improved the film transfer so as to almost eliminate gate shake.  Everyone was very excited about this much improved technology.

Now you can shoot with the latest video equipment and you can then go out and buy filters that will put in gate shake, grain, blur, film transfer curves, and make it all look like you used equipment that is 100 years old.

Telling a good story when writing, through audio, or visuals, depends far more on having a good script than all of the technology combined.  Remember, the technologies are only tools to tell the story.

Michael knows that I love technology, but let's get a little perspective on this.

Ray Maxwell
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Ray,

I remember Showscan. I believe it was shot 65mm at 60fps.  It looked incredibly detailed and fine grained...but the motion looked awful.  There was little motion blur in each frame (1/120 sec each) and the strobing of the motion was very ugly.  I'm not surprised that it never caught on.  The sound was spectacular for it's time though:)