Why 24 FPS?

Discussion in 'Movies' started by KylePete, Jan 5, 2004.

  1. KylePete

    KylePete Stunt Coordinator

    Joined:
    Dec 30, 2003
    Messages:
    91
    Likes Received:
    0
    Trophy Points:
    0
    I'm sure this has been brought up before, but I couldn't find anything doing a search.

    My question is: Why are films shot at 24 frames per second?

    I ask this because I grew up thinking that films were of the best quality possible...compared to something like sitcom shows. However, the motion doesn't seem very smooth in theaters or on DVD....compared to the TV shows shot at 30 fps.

    Is it because of the limits of film-shooting?

    I'm sorry if this is a stupid question or if it is posted in the wrong section.

    Thanks for any help or clarification.

    Kyle
     
  2. Alex Spindler

    Alex Spindler Producer

    Joined:
    Jan 23, 2000
    Messages:
    3,971
    Likes Received:
    0
    Trophy Points:
    0
    I did a quick search and it sounds like the addition of sound matched the change from 16 fps to 24 fps. Wether this was a necessity or a coincidence I don't know.

    However, I don't know anything the Internet doesn't know (and it is overflowing with incorrect information). I'm sure someone more knowledgeable will chime in with something more precise.
     
  3. Kami

    Kami Screenwriter

    Joined:
    Jan 2, 2001
    Messages:
    1,490
    Likes Received:
    0
    Trophy Points:
    0
    Because it gives films that special look. ANything that looks "professional" was shot at 24fps. The motion characteristics 24fps gives us is burned into our heads...that's why anything shot at 30fps or interlaced automatically screams amateur home video (at least to me). I love the look of 24fps and I hope they never change it. Even digital has moved to 24fps (including some Mini-DV cameras) so you know it is probably here to stay.

    More does not always mean better.

    And it is not a limit of film shooting. They often shoot at up to 72fps (maybe more sometimes) for slow-mo sequences (you would shoot at 72fps then slow it down to 1/3 speed so it would play at 24fps and then you would get smooth slow motion). Another example is a lot of the elven sequences shot in LOTR were shot at 33fps and slowed to 24fps to give a slightly different look.
     
  4. RobertR

    RobertR Lead Actor

    Joined:
    Dec 19, 1998
    Messages:
    9,955
    Likes Received:
    347
    Trophy Points:
    9,110
    24 fps is probably a compromise between cost (a higher frame rate would use more film) and quality (go much lower and flicker becomes more noticeable).
     
  5. KylePete

    KylePete Stunt Coordinator

    Joined:
    Dec 30, 2003
    Messages:
    91
    Likes Received:
    0
    Trophy Points:
    0
    Thanks for the info, everyone. I'm just wondering because slow pans across a landscape always seem to stutter in movies....at least to me.

    Thanks again,
    Kyle
     
  6. Leo Kerr

    Leo Kerr Screenwriter

    Joined:
    May 10, 1999
    Messages:
    1,698
    Likes Received:
    0
    Trophy Points:
    0
    One of the convenient answers is that it had to do with the addition of sound to film.

    Except it doesn't really work - a lot of stuff was being shot at 24fps in the early 20s, and sound-on-film didn't really happen until the late 20s. (Jazz Singer, for example, 1927, only had partial sound-on-film.)

    But 24fps may not be here to stay. A lot of people are doing frame-rate research, and would love to bump up to about 72fps. (Actually, they say 60fps is close to the magic point; 72fps gives 'em some margin.) Allegedly, there is a significant shift in how the brain processes the visual input that 'appears' to be more like 'reality.' IF Digital Cinema ever really catches on and surplants film in the general market, then such a shift is possible. Not, mind you, particularly likely, but at least possible.

    But as for the original query of, why 24fps, I remember hearing several different explanations. I can't remember any of 'em.

    Leo Kerr
    [email protected]
     
  7. Lew Crippen

    Lew Crippen Executive Producer

    Joined:
    May 19, 2002
    Messages:
    12,060
    Likes Received:
    0
    Trophy Points:
    0
    With the proliferation of HD video being used to shoot low budget movies (and some big-budget ones as well), many professionals are choosing 24 fps when they could easily shoot 30 or 60 fps.

    As Kami already mentioned, 24 fps is sort of burned into our brains for film—30/60 make us think we are watching TV or video.

    I’m sure that the movie industry is still trying to differentiate itself from TV—and will do so as long as we equate 24 fps to movies.
     
  8. Michael Reuben

    Michael Reuben Studio Mogul

    Joined:
    Feb 12, 1998
    Messages:
    21,763
    Likes Received:
    3
    Trophy Points:
    5,110

    I see this much more on DVD than in film, and on DVD it's the result of a (relatively) low resolution and MPEG compression. In my experience, 24fps on film is perfectly capable of rendering smooth pans across a landscape.

    M.
     
  9. KylePete

    KylePete Stunt Coordinator

    Joined:
    Dec 30, 2003
    Messages:
    91
    Likes Received:
    0
    Trophy Points:
    0
    Thanks, Lew and Leo.

    I suppose Hollywood will always want to differentiate their films from regular TV, but I still don't get why they wouldn't want to use higher frame-rates for smoother motion. I do see how 24 fps is burned into our minds for movies, but hasn't that standard been around for a long while?

    I'd actually love to see a comparison of the exact same scene shot at 24 fps compared to 30 fps or even 60 fps. Won't we think that old movies look "jittery" in the future when they use a much higher frame rate?

    I think it's been mentioned that 24 fps has a certain dream-like quality to it. I wonder what multiples of 24 fps (72, as Leo mentioned) would look like? Would that retain the "movie-look"?

    Thanks for the info and clarification, everyone. Sorry if I ask a lot of questions, but I love movies and want them to be their best [​IMG]

    Kyle
     
  10. Ray H

    Ray H Producer

    Joined:
    Jun 13, 2002
    Messages:
    3,482
    Likes Received:
    16
    Trophy Points:
    610
    Location:
    NJ
    Real Name:
    Ray
    So that's why film looks like film and tv looks like tv? never knew that!
     
  11. KylePete

    KylePete Stunt Coordinator

    Joined:
    Dec 30, 2003
    Messages:
    91
    Likes Received:
    0
    Trophy Points:
    0
    Oops, sorry, Michael. I was writing while you posted.

    I agree that DVD's can introduce un-smooth motion due to MPEG compression (By the way, does anyone know if HD-DVD will improve upon this?) However, I still notice it in theaters, too.

    This is why i don't like aging. I can't allow myself to wander into the world that movies create. When I was younger, I never thought to myself, "Gee, they need to focus the projector better in this theater."

    Thanks again,
    Kyle
     
  12. Alex Spindler

    Alex Spindler Producer

    Joined:
    Jan 23, 2000
    Messages:
    3,971
    Likes Received:
    0
    Trophy Points:
    0
    I imagine budget plays a part. Higher frame rate means more miles of film to shoot on. It would also increase the cost and complexity for special effects by a factor of 3 at least. That would be three times the number of frames to have a computer render and would increase the complexity and the need for precision for hand drawn art to work really well.
     
  13. Michael Reuben

    Michael Reuben Studio Mogul

    Joined:
    Feb 12, 1998
    Messages:
    21,763
    Likes Received:
    3
    Trophy Points:
    5,110

    If that's the only problem you've encountered with aging, consider yourself fortunate!

    M.
     
  14. KylePete

    KylePete Stunt Coordinator

    Joined:
    Dec 30, 2003
    Messages:
    91
    Likes Received:
    0
    Trophy Points:
    0
    You're probably right about cost and complexity, Alex.

    Michael, I can list all the problems with aging that I've encountered if you want me to [​IMG]
     
  15. Dennis Pagoulatos

    Dennis Pagoulatos Supporting Actor

    Joined:
    Feb 3, 1999
    Messages:
    868
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    CA
    Real Name:
    Dennis
    24 fps results in an overall dim, flickery image...

    Ok, it looks fine... until you see it compared side by side with the same thing at 60 fps or 72 fps. IMAX films are shot and projected at a higher frame rate (not sure what it is, but it's a lot more than 24fps, and they still have that "film-like" look that a few folks are nervous about losing!) and it is one of the reasons that they look so much "brighter" aside from all of the obvious increased resolution the larger negative gets you.

    24 fps is an archaic standard that will eventually be replaced, just like mono sound was. Sorry guys, but in this case, more IS better!

    I'd rather have the future digital theater formats be at something resembling film in apparent resolution (4000+ lines horizontal, subjectively) but at a MUCH higher frame rate like 72fps as a STANDARD.

    Think of computer displays. The VESA standard established decades ago, determined that something like 70HZ MINIMUM was the acceptable refresh rate (basically the FPS of your monitor) to reduce eye strain!

    So, if 70FPS is a MINIMUM standard for keeping your vision intact...why would you want to continue subjecting yourself to a dim, flickery 24FPS image....WILLINGLY!?

    It just seems stupid to me, and I LOVE film.

    -Dennis
     
  16. MatthewLouwrens

    MatthewLouwrens Producer

    Joined:
    Mar 18, 2003
    Messages:
    3,034
    Likes Received:
    1
    Trophy Points:
    0

    Wouldn't this also be due to the 3:2 pulldown used in converting 24 fps to 30 fps for NTSC. I expect you're used to the results of that conversion, in the same way that those of us in PAL countries are used to 4% speed up, but occassionally when I'm watching NTSC material, I can find the juddering in pans distracting.
     
  17. Artur Meinild

    Artur Meinild Screenwriter

    Joined:
    Aug 10, 2000
    Messages:
    1,294
    Likes Received:
    0
    Trophy Points:
    0


    I believe this is very much due to 3:2 pulldown... I also agree with those that yearn for higher frame rates like 60 or 72 FPS - it really gives a much smoother experience, but it is correct that it would increase special effect costs...
    Maybe a technique could be developed so special effect houses only needed to do the normal 24 FPS and a computer would extrapolate the 24 FPS into 72 FPS - that would be nifty wouldn't it??? [​IMG]
     
  18. Chris Mannes

    Chris Mannes Stunt Coordinator

    Joined:
    Aug 30, 2000
    Messages:
    56
    Likes Received:
    0
    Trophy Points:
    10
    The main reason that film looks like film, (IMAX included) and video looks like video has to do with how 'brightness' is recorded.

    Video tends to have a very linear progression of brightness. While Film is more logarithmic. (Much like the human eye.)

    I haven't been able to find any good articles on this. It was from an old lighting textbook from college that I originally learned about it.

    And it probably doesn't apply to HD cameras, since at the time the textbook didn't take such things into consideration.

    Chris M.
     
  19. RobertR

    RobertR Lead Actor

    Joined:
    Dec 19, 1998
    Messages:
    9,955
    Likes Received:
    347
    Trophy Points:
    9,110


    Good luck on convincing movie makers that it would be worth the extra cost.
     
  20. Andy_G

    Andy_G Stunt Coordinator

    Joined:
    Jun 29, 2000
    Messages:
    212
    Likes Received:
    0
    Trophy Points:
    0
    Would it be possible to do 120 fps? This would greatly increase temporal resolution while also allowing for backwords compatiblility with both 24 and 30 fps sources. Expensive, but sharp.

    Also:Everything you ever wanted to know about temporal resolutaion. http://webvision.med.utah.edu/temporal.html
     

Share This Page