# Frames per second to create motion **URL:** \ **Category:** Factual Questions\ **Created:** [April 16, 2006, 3:58am UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848 "2006-04-16T03:58:32Z")\ **Posts on this page:** 13\ **Page:** 2
**Author:** ![Walloon](https://avatars.discourse-cdn.com/v4/letter/w/fbc32d/32.png) [@Walloon](https://boards.straightdope.com/u/Walloon)\ **Post date:** [April 17, 2006, 4:23pm UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/21 "2006-04-17T16:23:08Z")
> [@commasense](#): > > Finally, consider what a 24/25 disparity would mean for any Hollywood release shown in Europe or a European film shown in the US: either it would run 4% too fast or too slow, with obvious effects on appearance and the sound track 24 fps films are routinely shown at 25 fps on British and French television, which operate at 25 frames per second/50 fields per second. Having seen this, I can say that the effects aren’t that obvious unless you time the length of the film. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 17, 2006, 4:42pm UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/22 "2006-04-17T16:42:09Z")
> [@Walloon](#): > > 24 fps films are routinely shown at 25 fps on British and French television, which operate at 25 frames per second/50 fields per second. Having seen this, I can say that the effects aren’t that obvious unless you time the length of the film. As I said just two sentences later, this is done not by running the 24 fps film at 25 fps, but by repeating one frame’s worth of information each second during the film-to-video transfer process. (PAL is it the European television format.) You _would_ notice a film running 4% too fast or too slow. It wouldn’t appear natural, and familiar sounds and voices would be noticeably shifted in pitch. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [April 17, 2006, 5:04pm UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/23 "2006-04-17T17:04:00Z")
> [@commasense](#): > > As I said just two sentences later, this is done not by running the 24 fps film at 25 fps, but by repeating one frame’s worth of information each second during the film-to-video transfer process. (PAL is it the European television format.) You _would_ notice a film running 4% too fast or too slow. It wouldn’t appear natural, and familiar sounds and voices would be noticeably shifted in pitch. [Not according to this site:](http://www.orlandoavidusers.org/pp_archive/pp_frame.html) > [@](#): > > A different approach is used in PAL countries. **24fps films are sped up** as they run through the telecine to match the PAL video rate of 25fps. **There is no pulldown** , but there is a noticeable 4% speed increase, resulting in higher-pitched soundtracks. Although European theatrical films are generally also filmed at 24fps, many film-originated television productions are shot at 25fps, so that a one-to-one relationship with video and sound is maintained. These various frame rates are perceived differently in other countries. American (and other NTSC) viewers are used to 30fps (29.97) interlaced video, so when they first see PAL images, the TV sets seem to have a more pronounced strobe. This quickly wears off as our eyes (and brains) adjust. Pulldown and the lower image resolution of NTSC tends to look odd to PAL viewers when they first see NTSC images. ---
**Author:** ![Walloon](https://avatars.discourse-cdn.com/v4/letter/w/fbc32d/32.png) [@Walloon](https://boards.straightdope.com/u/Walloon)\ **Post date:** [April 17, 2006, 5:17pm UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/24 "2006-04-17T17:17:37Z")
[Television Standards: Formats and Techniques](http://www.paradiso-design.net/videostandards_en.html#transfer): > [@](#): > > For the transfer onto PAL the film is simply accelerated. PAL needs 50 fields/s. Two fields (: n1 and n2) of the 2nd second of the film are still “pressed” into the first second - marked-off with the red dotted line - of the PAL video. Thus the so-called PAL Speedup emerges. PAL films are played 25/24 ? 4,167 % faster than the original film in the cinema. We can also say that the PAL length is 24/25 times longer compared to the original film. That means that the PAL length is 4 % shorter. Due to the acceleration of the film some people notice that the tone pitch is increased with PAL films. Two fields are displayed within 1/25 s = 40 ms. [PAL Timecode for Film and 1080p/24 Production](http://24p.com/PAL_TC.htm): > [@](#): > > When 24-frame captured material get transferred to video, the material is transferred at 25fps increasing the playback rate by 4.1%. This allows the video to have a 1:1 relationship with the film. During this transfer, the 24-frame timecode now counts as 25-frame timecode, making it usable in all postproduction editing systems. The only issue is the pitch of the transferred audio. It is now raised by .7 semitone. [PAL vs. NTSC](http://www.michaeldvd.com.au/Articles/PALvsNTSC/PALvsNTSC.asp): > [@](#): > > Movies on PAL DVDs play back 4% faster than their NTSC counterparts. The great majority of people will never notice this, but for a small minority, this is an intolerable artefact. [PAL Basics](http://www.editorsguild.com/newsletter/MarApr02/tip_pal_murray.html): > [@](#): > > European filmmakers usually work in TV and are comfortable with running everything at 25 fps throughout post production. When shooting a feature (at 24 or 25 fps) they often decide to finish everything, including scoring and mixing, at 25 fps, then pitch-shift up the printmaster 4% so that the composer’s intended pitch is preserved when the film is slowed down to 24 fps in projection. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 17, 2006, 5:42pm UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/25 "2006-04-17T17:42:17Z")
Okay, I stand corrected on this point. (European TV practices aren’t one of my areas of expertise.) In searching for cites, I came across a reference to a pulldown scheme that repeated one field at the 12th frame and a second at the 24th so as to bring 24 fps material up to 25 fps with no change in speed or pitch, and I assumed that this was the standard way it was done. But I guess not. I’m frankly shocked that filmmakers, composers, and other creative types would accept this distortion of their work, but I guess the practice originated at a time when there was no practical alternative, and everyone has just gotten used to it. Thanks for the info. ---
**Author:** ![Cartooniverse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cartooniverse/32/3084_2.png) [@Cartooniverse](https://boards.straightdope.com/u/Cartooniverse)\ **Post date:** [April 17, 2006, 9:11pm UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/26 "2006-04-17T21:11:36Z")
> [@commasense](#): > > I’m sorry, but you’re mistaken on this point. No, I’m not. And, nice to meet a fellow IA brother. 🙂 Now it’s incumbent upon me to put my hands on a very clear scan of the shot of Kubrick. On location. Far from a theatre or projector. Standing next to his cameras. That are marked **25fps**. I’ve filled out a LOT of camera reports in my time, and never did I have to mark the frame rate. The body is marked as such so that folks know which body is shooting footage for which market ( I suspect. Knowing his penchant for total control, he likely shot both ways. Genius. Lunatic. Whatever. 😃 ) Hard to believe that the two major camera manufacturers on the planet ( arguably… ) both make the cameras switchable to 25fps- just to serve the needs of one particular television viewing audience. The frame-duping scheme outlined above is more logical- why even MAKE a 25fps camera body unless you shoot and project at the same rate of speed? I’ll email a colleague in London who knows better. And, ask him what frame rate his cameras are set at when he shoots. 🙂 ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 17, 2006, 10:58pm UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/27 "2006-04-17T22:58:32Z")
> [@Cartooniverse](#): > > > [@commasense](#): > > > > I’m sorry, but you’re mistaken on this point. > > No, I’m not. And, nice to meet a fellow IA brother. Oh, yes, you are, and the sooner you admit it, the easier it will go for you. 😃 (And I’m not a union member.) **Cartooniverse** , I don’t doubt that you saw what you saw. I just think you’re jumping to the wrong conclusion. If I had any tiny doubts before, the cite from John Pytlak referencing the SMPTE standard eliminated them. Although I haven’t met John face to face, I’ve e-mailed him many times, and he is without doubt one of the most knowledgeable people in the film business. Ask anyone. What do you mean by “one particular television viewing audience”? The television production market for 25 fps cameras is basically the whole world except for the US, Canada, and Japan, since both PAL and SECAM are 25 fps. So it should be no surprise that many cameras can shoot both 24 and 25 fps. But 35mm projectors in theaters around the world all run at 24 fps, and have since the 1930s. It is the worldwide theatrical standard. I’ve provided the cites. You’ve only spoken about cameras, a point I concede, but which doesn’t prove your point. Where are your cites for films being presented theatrically at 25 fps? (Despite my virtual certainty on this point, I have sent an e-mail to a friend who is the chief projectionist at the National Museum of Photography, Film, and Television in Bradford, UK. If there is any theatrical use of 25 fps, he’ll know about it.) ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [April 17, 2006, 11:14pm UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/28 "2006-04-17T23:14:48Z")
> [@DanBlather](#): > > Silent movies used 20 FPS. When they added sound they needed to go to 24 FPS so that the lips would sync up with the voice; i.e., to have enough lip “samples” to make it look realistic. No, the increase in speed was due to the fact that the sound track had to move at the equivalent of 24 fps to reproduce correctly. Silent films had no problem with realistic lip movements prior to that (there was the classic example of the lipreader’s association complaining about a silent film in which, when the actor was carrying the leading lady and she was supposedly whispering how much she loved him, her words actually were, “If you drop me, you son of a bitch, I’ll kill you.”). ---
**Author:** ![Cartooniverse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cartooniverse/32/3084_2.png) [@Cartooniverse](https://boards.straightdope.com/u/Cartooniverse)\ **Post date:** [April 18, 2006, 12:04am UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/29 "2006-04-18T00:04:02Z")
> [@commasense](#): > > Oh, yes, you are, and the sooner you admit it, the easier it will go for you. 😃 (And I’m not a union member.) -Flinches- Easy there, Capone. Or should I say, Edison. Back in the day, my Great Uncle Raymond was a TrustBuster. He’d go out, on behalf of the Trust and find renegade nickleodeon houses. He, and his buddies, would literally beat up the projectionist and burn the prints. This took moments of course, because they were nitrate prints. When I found out about his nepharious past, I was horrified. He died in the mid-1970’s, which is a pity because after he stopped being a legbuster, he was a charter member and one of ten founders of the IATSE Projectionists Union. He then went to work at the Reeves Audio Research Labs, on Long Island. ( Those familiar now know it as Reeves TeleTape). He was, incredibly, in on the fundamental research and development of two-system, and then finally single-system on-film sound for movies. Kinda cool, except that he was apparently a bigoted hateful racist angry man. Doesn’t negate his past, though. My Great Aunt showed me his IA card, and said she’d be glad to call the Union to help me get in. ( She didn’t realize that my local didn’t have shit to do with her local. It was a lovely gesture anyway ). Having shared this little tale, I must admit you are correct. Film cameras can capture at a variety of frame rates. As has been linked in this thread, silent camera ops used to juice the shots when the Director told them to, to either have them play back faster ( Keystone Cops ) or slower for that slo-mo romantic effect. However, projectors do run at 24fps. Sorry I was so stubborn about that. This lips thing? I don’t buy it, I’m sorry. You shoot at 18fps, you run at 18fps, the lips move like they ought to. As proven earlier, you record an lp at 16 rpm, and play back at 16 rpm, nobody sounds like Alvin and the Chipmunks. The frame rate was driven by the well-documented persistence of vision cites, not by a threshold of recording sound. IMAX manager, eh? Got any clips laying around from the Space Shuttle film?? 🙂 ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 18, 2006, 1:42am UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/30 "2006-04-18T01:42:20Z")
Well, I’m glad you finally saw the light, and that things didn’t have to get, you know, _unpleasant_. 😃 What was it persuaded you, if you don’t mind my asking? > [@Cartooniverse](#): > > IMAX manager, eh? Got any clips laying around from the Space Shuttle film?? Yeah, as a matter of fact, I do. Where should I send them? (Really.) So if we can get back to the OP, now that our slightly off-topic wrangling is done, [here](http://www.film-tech.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=006820) is a link to an interesting thread in a forum for projectionists about how the 24 fps rate was established. ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [April 18, 2006, 1:48am UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/31 "2006-04-18T01:48:54Z")
I forgot to mention that to get to the thread in my link above, just click on “I agree with both sentences” on the first page you get to. ---
**Author:** ![Cartooniverse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cartooniverse/32/3084_2.png) [@Cartooniverse](https://boards.straightdope.com/u/Cartooniverse)\ **Post date:** [April 18, 2006, 2:46am UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/32 "2006-04-18T02:46:30Z")
> [@commasense](#): > > Well, I’m glad you finally saw the light, and that things didn’t have to get, you know, _unpleasant_. 😃 What was it persuaded you, if you don’t mind my asking? Stark terror. Of course. 😉 I emailed you earlier today. ---
**Author:** ![Beware\_of\_Doug](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Beware\_of\_Doug](https://boards.straightdope.com/u/Beware_of_Doug)\ **Post date:** [April 18, 2006, 10:01am UTC](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848/33 "2006-04-18T10:01:47Z")
> [@David Simmons](#): > > I thought interlacing was done in order to get a reasonable horizontal scan frequency while at the same time preserving vertical resolution. At first – I’m talking mechanical scanning days here – it _was_ done to reduce flicker. The Sanabria system, used by several short wave stations in the midwest, did it with only 45 lines resolution in the early 30s. [Previous page](https://boards.straightdope.com/t/frames-per-second-to-create-motion/352848.md?page=1)