This is a guest post from veteran Director of Photography and long-time Comprehensive Media friend Matt Coale. Matt has worked on Comprehensive Media projects for more than 20 years. This is a great post on the history, confusion and controversy surrounding the 24P frame-rate.
By Matt Coale
(My humble observation as a veteran Director of Photography)
Since the beginning of motion pictures, budgets have dictated the frame rate at which we view films. The faster the film runs through the camera, the quicker money leaves the producer’s pocket. With the new wave of digital cinematography and digital projection, it’s time we released the chains of “minimum frame rate” and have a better visual experience in the cinema and at home.
Before I present my case, here is a brief lesson in cinema and television technology.
A Simplified Lesson in Formats:
- Standard Definition (SD) video has 525 lines of horizontal resolution.
- High Definition (HD) video has 1080 lines of horizontal resolution.
- These lines are made of tiny pixels. They are recorded and projected in horizontal lines very quickly, many times per second. The more lines of resolution, the greater the picture clarity.
- Currently, when recording and presenting digital video, you have the choice of a progressive (24P, 30P) or interlaced (60i) format.
- Progressive scanning is a way to record and project moving images in which all the lines of each frame are displayed at once.
- Interlaced scanning records and projects two “fields” for each video frame. The first field contains the even numbered lines. The second field contains the odd numbered lines. This technique doubles the perceived frame rate and is designed to reduce “flicker”. Two fields create one frame. 60i equals 30fps (frames per second).
A Brief History of Frame Rates
From the beginning of the film industry, 35mm film has been a costly investment. To save money, producers strived to shoot the minimum frame rate and still provide a pleasing visual experience.
In the silent film era, 18fps (frames per second) was determined to be the minimum frame rate acceptable to audiences. By putting a shutter on the projector, and projecting each frame three times, the viewer’s persistence of vision created a fluid, realistic representation of realism.
18fps acquisition and 18fps projection were acceptable for the cinema audience of that era.
In 1927, The Jazz Singer brought picture and sound together in America’s first feature length “talkie”. The landmark film used a phonograph to reproduce the sound. Technicians and engineers began the task of adding sound to picture in a single system. An audio track was soon married to the film print. However, in order to effectively reproduce the sound, the frame rate of the projector needed to be increased to a minimum of 24fps. Consequently, the frame rate of the recorded/projected image was increased to 24fps.
24fps acquisition and 24fps projection were acceptable for the cinema audience of that era.
Around that same time, the “step-child” of cinema and radio emerged: Television.
In 1941the National Television System Committee established the standards for American television broadcasting. The established scan rate of 60i (60 interlaced fields or 30 frames per second) was based on the 60 Hz cycle of alternating current.
60i(30fps) acquisition and 60i(30fps) projection were acceptable for the television audience of that era.
Two Worlds Collide
During the 1950’s television sets began to permeate American homes. In the mid 1950’s King Kong was the first feature length motion picture shown to American audiences via the new television medium. It was a huge success. Motion picture studios and television networks now had a new source of programming and income.
Engineers and technicians were charged with the task of transferring motion pictures shot at 24fps to a 60i(30fps) medium. Simply speeding up the film was very obvious to the eye and ear. A technique of turning every second frame of film into three fields of video (2:3 pulldown) seemed to solve the timing problems but introduced “strobing” and “stutter” into the final product. Also, television cropped out 1/3 to 1/2 half of the image. The filmmakers cried out: “How can you deface our artistic work?” But the studios owned the films and there was money to be made!
24fps acquisition and 30fps projection (via a 2:3 pulldown) were acceptable for the television audience of that era.
Over time, that strobing and stutter became engrained in the American psyche and directly associated with top quality motion pictures. Europeans watching American TV would stand aghast and ask, “How can you watch that?”
Change?
In the 1950’s television audiences grew and cinema audiences diminished. Hollywood tried every gimmick they could conceive in order to reclaim their audience. The era saw an array of wide-screen formats come and go. 3-D and Smell-O-Vision had brief success. Technically speaking, not much changed. Films continued to shoot at 24fps and television was recorded and broadcast at 60i(30fps).
In the late 1970’s and early 1980’s, Douglas Trumball (a motion picture genius and pioneer) introduced Showscan, which used 65mm film shot and projected at 60fps. This process rendered a motion picture that was not only extremely high in definition, but was dramatically smoother and more realistic. When biometrically tested with audiences, as the frame rate increased, so did the viewer’s emotional response. This response peaked around 72fps.
The numbers are in. The theory is quantified and proven; faster is better. But try to convince Hollywood producers to shoot and project 65mm film at 60fps. The increase in shipping costs alone was staggering. Showscan never gained traction. Trumball was way ahead of his time. Showscan declared bankruptcy in 2002.
24fps & 24P
In 1999 The Blair Witch Project hit the theatres. It was one of the first successful indie features to shoot on a video format and be transferred to film for 35mm distribution. Produced on a micro-budget, it went on to gross over $248 million worldwide. Everyone in the film industry took notice.
The challenge of getting a project shot on a 60i video format transferred economically to a 24fps film format had been overcome.
Shortly thereafter, manufacturers began releasing video cameras that could record at 24P. One frame of video equaled one frame of film. Now, indie films could shoot on a video format at 24P and exhibit on a film format running at 24fps: a process that cost pennies to the dollars.
The door for low-budget, independent films opened wide. The reviews, blogs and press releases spread the gospel of 24P throughout the world. Students, professionals and those in-between rejoiced: “We have been delivered from the bondage of film!” For documentations and low budget filmmakers, video acquisition at 24P was a godsend and they were right!
But a funny thing happened on the way to the theatre…
Sitting on the sidelines, feeling forsaken, television producers longed to be part of the celebration. There was a new “shiny ball” and they wanted to touch it.
I Be Hypnotized
“24P…24P…I must shoot 24P !!” was the new mantra for television producers.
The marketing said: “24P looks like film”. The blogs said: “24P looks like film”. Projects shot at 24P and transferred to film “looked like film” (duh). There it was, in black and white: “24P looks like film!”
If you repeat something enough…it becomes truth.
A lot of the television producers and students drank the kool-aid. They longed to become part of the “new wave” and shoot their projects at 24P because “it looks like film”.
Shooting 24P on a project destined for the cinema? It makes complete sense. 24P for a television project…are you kidding? Did you ever bother to do a side-by-side comparison of 30P vs. 24P displayed on a television? I have! You would have to be blind to think 24P has a higher quality image.
Being a good DP, I would acquiesce to a producer’s desire. I shot a lot of TV/DVD projects at 24P to please production. That’s my job; to make them happy. Personally, I hated the look of 24P for television. Why intentionally add degrading artifacts into your picture? I would lobby for 30P, which I prefer for broadcast TV. Some producers trusted my judgment. The insecure ones trusted the market (everyone else shoots 24P). Whatever their choice, I gave it 100%.
For the next few years, 24P permeated the broadcast industry. During the 24P/30P/60i discussions, I privately conducted a survey of 24P proponents. I would quietly question them on their knowledge of 24P and gather my evidence. To my surprise, 99% of the professionals did not know the history of 24P and why “it looks like film”, but they were convinced it was best. Even more frightening was the fact ALL the students coming out of film school were convinced 24P was the only video format to shoot.
To be fair, I knew what they meant by “it looks like film”. The strobing and stutter in their project matched their favorite Hollywood movie viewed on TV. But let’s be clear: What is seen on TV does NOT match the exhibition of the film in the cinema or the artistic vision its creator. Films in the cinema are shot at 24fps and projected at 24fps. It’s a 1:1 ratio. Most projects shot for television are recorded at 30fps and projected at 30fps; another 1:1 ratio.
In a perfect world, you exhibit your film at the same rate you record it. Why would you intentionally degrade your film at the moment of capture? I’ve banged my head against this wall for years. But then…some are still shooting BetaCam and I’m sure there are those still using floppy disks on their computer. Many are resistant to change. All I can do is present the history of 24P and hopefully a light will shine into the darkness.
Will Bilbo finally slay 24P?
We are working in an ever-changing, digital revolution. Film acquisition is slowly declining. In the end, it’s a “business”. The cost savings of digital acquisition and digital exhibition not only saves money, it’s better for the planet. Besides that, the digital images are getting better each day.
In the past, frame rates were controlled by the cost of film. The more film you burned, the more it cost production. With digital acquisition, the cost of increasing the frame rate is pennies. All it requires is a little more digital storage. Digital projectors in theatres are completely capable of projecting at higher frame rates.
In March 2011, Peter Jackson began production of The Hobbit. The production is shooting and projecting at 48fps for “enhanced clarity and smoothness”.
In March 2011, filmmaker James Cameron, gave a presentation promoting the idea of moving motion picture technology to faster frame rates such as 48 or 60 fps, saying that he would be shooting the sequel to his 2009 film
Avatar at one of those two frame rates.
The jury is in. The verdict is “faster frame rates increase clarity, motion and resolution”.It’s time we get away from this archaic use of “minimum frame rates” like 24P. Besides, if you were a true cinema purist, you would shoot at 18P !
It’s only a matter of time until we move onto 48P, 60P and 72P. Let’s start today. It’s time we move forward. It costs very little to have a better visual experience. Hopefully, The Hobbit will bring a quick death to the myth of 24P! It won’t happen soon enough for me.
Very insightful. Great points. What effect does shutter speed and angle have on 30p?
Are there optimum settings for those while shooting at higher frame rates to still retain that ‘film look’?
Julian,
Thanks for your feedback. I’ve asked Matt to respond to your questions.
Joel
Julian,
Thanks for the compliment and your question. I’m sure you have forgotten more than I know about cinematography, but I’ll answer as best I can. Forgive me if this is a bit simplistic. I want to make sure all the readers understand the context of your question:
“What effect does shutter speed have on 30P ?”
Since we are comparing “film” to “digital” I’ll try to explain how I approach the transition.
As the frame rate increases (from 24 fps) so does the shutter speed. Frames are recorded and projected at a faster rate. Visual information is presented at a faster rate (about 25%). Picture definition is increased. Motion is smoother and more realistic.
Shutter speed for a film camera is calculated by multiplying the shutter angle by the inverse of the frame rate.
The mechanical shutter of a film camera is a 360 circle. The opening of the shutter is variable. Typically, the opening of the shutter is 180 degrees. When I shoot film for NTSC broadcast, I shoot at 30fps. Using those numbers, the shutter speed is calculated as follows:
180 / 360 x 1 / 30 = 1 / 60
Each frame of film is exposed for 1/60 of a second.
You can replicate that look in the digital world by shooting at 30P (progressive scan rate) and using the digital camera’s electronic shutter set at 1/60. As you increase the frame rate, you dial in a faster shutter. If you shoot at 60P, set the electronic shutter to 1/120. It makes sense to shoot television at multiples of 30.
I’m positive, in the near future we will see frame rates increase in television (30P and 60P) and in the cinema (48P, 60P, 72P). It will be another artistic choice like lens size, aspect ratio and selective focus.
Increased frame rates will look different. Some filmmakers will shy away and some will exploit the new tool and give us a completely new visual experience. Since the dawn of the moving image, each succeeding generation has been able to absorb and retain information at a faster rate. It only makes sense our new cameras do likewise.
Entire books are written on the “film look”. So many elements come together to give us that “look”. As new cameras and electronic tools are invented, this “look” will be expanded into places yet imagined. The “film look” is not solely defined by 24fps.
For 100 years filmmaking was restricted to a mechanical and photochemical world. Digital acquisition, digital post-production and digital projection will open up a whole new “look” in the cinema and at home.
I’m advocating getting away from 24fps (for cinema) and 24P (for television). It never fit our electrical cycle and 24P (with the 2:3 pull down) for television looks horrific compared to higher frame rates.
I hope that answered your question…
I believe that you are in the minority. You say that you have sat down and compared the two, great so have a lot of other professionals and saying that 99% of professionals don’t know the history has little to do with the actual reason that people prefer 24p.
30p and higher frame rates are great for sports or news because it eliminates the motion blur, so it looks like you are looking “through a window” making you feel like you are at the game or the reporter is talking to you. But for films you are not necessarily there to look through a window, or maybe you are. In my opinion, film is the opportunity to escape the “real” world and get lost in a story. There needs to be that separation between you and screen, otherwise why not just go look our your window.
Whether it is history or cost that has established these frame rates, the point is that we have associated 24p with story. 30p looks like a soap opera, and I really don’t want what I shoot to be associated with a soap opera but rather what I see in films like “The Tree of Life” or “Girl with the Dragon Tattoo”.
When I see 30p I cringe, so I guess we are on opposite side of the coin.
Agree to disagree.
Brandon,
Thanks for your comment.
Actually Soap operas and sporting events are shot at 60i not 30p – there is a difference. Also, we’re not aware of any 3:2 pulldowns for theatrical release. We don’t think it’s been done. Do you have any knowledge otherwise, cause we would love to know.
Thanks!
I think I may have confused the issue using 30fps in conjunction with 60i.
60i (30fps) is not the same as 30P. Soap operas and sports are generally shot at 60i(30fps) not 30P as stated. I’m sorry if I created confusion. It’s easily done when discussing formats.
I agree with you. I would not shoot my “film” with an interlaced format. A progressive format imitates the theatrical experience much closer than an interlaced format. The point I was trying to make was “for television” not for the theatre. TV is based on a 60Hz cycle, so multiples (or fractions) of 60 fit much better into this format. Digital movie theatres will soon have a near limitless option of frame rates, which puts a lot more tools into the hands of filmmakers. Hurray! Maybe one day, television broadcast will follow suit. Then your film will be projected at the same rate it was recorded.
24P will still be an option for film artists. The 24P issues arise when broadcast on current television signals (based on 60Hz). Some films artists love the motion blur, strobing and artifacts that come with turning 24P into 60i. Some people prefer vinyl records over digital recordings and manual typewriters over computers. Vive la différence!
Being a working DP for 28+ years, part of my job is to see what is trending and attempt to stay ahead of the curve. I would consider James Cameron and Peter Jackson good barometers of filmmaking trends. It appears our future holds higher resolution, higher frame rates and a greater sense of realism in movie theatres.
Fads come and go and these fads can make your film look “dated”. In the 1990’s you couldn’t shoot a music video without a dutch head, swing/tilt lenses and shooting film at 24fps. If I was asked to recreate this era, that’s exactly what I’d do. I would create a hand-held, Kodachrome look to represent the 1970’s. In the future, we’ll create a 3:2 pulldown, with all its strobing and motion blur, to represent the years 2000-2010.
The 24P fad for television has become “dated”. I’m moving forward. I gotta work!