Notes on Format: 48 FPS, Digital, 3D, and IMAX

48 FPS?

Director Peter Jackson shot The Hobbit, Parts I and II (2012, 2013) in 3D at 48 fps. He wrote on his Facebook page (see here):

We are indeed shooting at the higher frame rate. The key thing to understand is that this process requires both shooting and projecting at 48 fps, rather than the usual 24 fps (films have been shot at 24 frames per second since the late 1920’s). So the result looks like normal speed, but the image has hugely enhanced clarity and smoothness. Looking at 24 frames every second may seem ok--and we’ve all seen thousands of films like this over the last 90 years--but there is often quite a lot of blur in each frame, during fast movements, and if the camera is moving around quickly, the image can judder or “strobe.”

Shooting and projecting at 48 fps does a lot to get rid of these issues. It looks much more lifelike, and it is much easier to watch, especially in 3-D. We’ve been watching HOBBIT tests and dailies at 48 fps now for several months, and we often sit through two hours worth of footage without getting any eye strain from the 3-D. It looks great, and we’ve actually become used to it now, to the point that other film experiences look a little primitive. I saw a new movie in the cinema on Sunday and I kept getting distracted by the juddery panning and blurring. We’re getting spoilt!

Originally, 24 fps was chosen based on the technical requirements of the early sound era. I suspect it was the minimum speed required to get some audio fidelity out of the first optical sound tracks. They would have settled on the minimum speed because of the cost of the film stock. 35mm film is expensive, and the cost per foot (to buy the negative stock, develop it and print it), has been a fairly significant part of any film budget.

So we have lived with 24 fps for 9 decades--not because it’s the best film speed (it’s not by any stretch), but because it was the cheapest speed to achieve basic acceptable results back in 1927 or whenever it was adopted.

Now that the world’s cinemas are moving towards digital projection, and many films are being shot with digital cameras, increasing the frame rate becomes much easier. Most of the new digital projectors are capable of projecting at 48 fps, with only the digital servers needing some firmware upgrades. We tested both 48 fps and 60 fps. The difference between those speeds is almost impossible to detect, but the increase in quality over 24 fps is significant.

Film purists will criticize the lack of blur and strobing artifacts, but all of our crew--many of whom are film purists--are now converts. You get used to this new look very quickly and it becomes a much more lifelike and comfortable viewing experience. It’s similar to the moment when vinyl records were supplanted by digital CDs. There’s no doubt in my mind that we’re heading towards movies being shot and projected at higher frame rates.

Academy white papers on the “Digital Dilemma”

X-tra Large

70 mm is the largest film size in use today. It was invented in the 1950s, and had its big-big screen debut for the musical Oklahoma! (1955). While 70 mm is expensive and cumbersome, it has exceptional clarity, resolution and depth, because it has more physical area than 35mm film and therefore captures significantly more detail. Some classic movies, including Lawrence of Arabia (1962), My Fair Lady (1964) and The Sound of Music (1965), were all shot on 65 mm film, and, as transformed through the finishing process, projected on 70 mm. But of course, you need projectors that can show 70 mm – and there are very few of them. When director Kenneth Branagh made Hamlet in 65 mm in 1996, the prints had to be downsized to 35 mm so they could be projected in cinemas, and it was the last conventional movie shot in 65 mm. Today, 65 mm film, which is actually run sideways through the camera to have a larger area for each frame, is used primarily for IMAX movies because IMAX projectors – the ones that still use film – are calibrated for 70 mm. For IMAX, the 65 mm film is printed onto 70 mm film for projection purposes; the extra 5 mm are used for audio-track or other non-image purposes. Occasionally, large visual sequences for big studio movies may be shot on 65 mm because it captures more image detail, as happened recently with The Dark Knight (2008) and The Dark Knight Rises (2012).

3D information