What exactly is 70mm print and why does anyone care?

Question

There has been a bit of controversy lately over the release of Tarantino's Hateful Eight movie. As I understand it, the movie was scheduled to play in a particular theater in Los Angeles that plays 70mm format. Disney chose to push/force/coerce/convince/whatever this theater into showing The Force Awakens instead.

This has caused a rather large uproar from both Tarantino, as well as many of his fans.

I will be honest, before I read this story I had never heard the term "70mm" before in my life; I only last week learned that there is a theater in my area that screens 70mm prints. Now I'm wondering what the big deal is, how these are any different from the versions shown at my usual theater, and why this format seems to have suddenly, out of nowhere (at least from my perspective) become a big deal.

Answer 1

There are several orthogonal issues here:

• The physical size of the film the movie was shot on (the negative).
• The physical size of the film the movie is projected from (the print).
• How the frame is composed on that film, which is related to the aspect ratio.

Some of the comments and other answers are conflating various aspects, which can cause more confusion than clarification. For example, others have implied the 70mm and IMAX are the same thing. While it's true IMAX does project from 70mm prints, 70mm prints are used in a variety of other, non-IMAX formats.

Before the switch to digital, most commercial movies were shot on 35mm negatives and then distributed to theaters as 35mm or sometimes 70mm prints. (Yes, some 70mm prints are sometimes made from 35mm masters.)

A few big budget, "big screen" movies were sometimes shot in 70mm and distributed to big theaters on 70mm prints and smaller theaters on 35mm prints.

The sizes, 35mm and 70mm, refer to the width of the film itself. This width includes the room for the sprocket holes and analogue audio tracks. Some digital audio tracks use the spaces between the sprocket holes. I believe (but correct me if I'm wrong) that magnetic audio tracks are not included in that width.

Most film runs through the projector vertically (big exceptions are true IMAX and VistaVision), so the width the frame is limited by the width of the film minus the width of the sprocket holes and analogue audio tracks. Thus the width of a frame on a 35mm print is a bit narrower than 35mm.

The sprocket holes are often called "perfs," and many formats are thus referred to as a number of "perfs." That is, as the number of sprocket holes from one frame to the next. A typical frame size for 35mm prints is 4-perf. Thus the height of the frame was limited by that number. For 70mm, I believe common formats were 7-perf, but I don't have a source for that.

The aspect ratio is the ratio of the width to the height. In olden times, movies were pretty square, much like old television sets. To compete with television, the studios introduced different aspect ratios (typically wider) in order to make the movie experience seem more immersive than television.

Given that the width and height of the frame both have upper bounds, there are only a few ways to adjust the aspect ratio:

1. Use less than the full height available on the frame, and use a telephoto projection lens to compensate for the diminished height.

2. Shoot (or print) the frames with an anamorphic lens that squishes the image horizontally to fit it onto the film, then project with the complementary lens that stretches it back out. This is typically done for the widest of wide-screen formats. A telltale artifact is that lens flares appear as ovals rather than circles.

3. Run the film horizontally. The height is limited by the film size minus sprocket holes, and the width is limited by however many perfs you choose. This is what traditional IMAX does. (Traditional IMAX also uses 70mm film exclusively.)

Given identical aspect ratios, 70mm film gives far more area per frame, which means it can be projected larger or will have better clarity and detail when projected as the same size as a comparable 35mm print.

Some movies are shot in a variety of formats, but mastered into a common format during editing and post production. For example, the original Star Wars films used old VistaVision cameras for many of the motion-controlled model shots, even though everything else was probably shot with traditional cameras that ran the film vertically.

In the case of this Tarantino film, I suspect it was shot on 70mm using anamorphic lenses in order to make a super-widescreen. IMDB confirms.

Answer 2

The difference is that 70mm film is, from a simple mathematical perspective, twice as big as 35mm film.

70mm film is shot horizontally in the frame where as 35mm is shot vertically. This gives directors a much larger canvas to shoot on, with increased resolution (up to 18k in some cases, compare that to 4k televisions that are just hitting the market), as well as better color depth.

Further, true IMAX or 70mm projection screens are more square in shape, as you can see from the image included above. Overall this helps to provide a far more immersive experience for audiences as your entire visual field is filled with what's on the screen.

However, The Hateful Eight is also hitting on a lot of "film nerd" items, such as the fact it was filmed using the same lenses they used to film Ben-Hur. To quote Tarantino in his interview with Stephen Colbert:

"And when I say that, I don't mean lenses like the ones they used to film Ben Hur, I mean the actual lenses they used to film Ben-Hur."

The lenses used allowed them to film in what's referred to as Ultra Panavision 70, meaning the frame will have an aspect ratio of 2.76:1, making it exceedingly wide by most modern standards, and the first film to be released in that aspect ratio on 70mm film in nearly 50 years. See here for more information on that.

The roadshow Ultra Panavision 70 version will also be a longer cut, including an overture opening plus an intermission.

So, the long and short of why these will be different from what most other theaters get is they'll have a much, MUCH larger picture, with higher image and color quality. It's an experience that the vast majority of theaters simply cannot provide anymore, so much so that since 2014 the Weinstein company has been paying to outfit more theaters with 70mm projectors so they can show the roadshow version of The Hateful Eight (sadly they ended up coming up short by about half). Basically it's a film nerd's dream if they can see the film presented in its intended format.

Answer 3

65mm negative. When the audio track is added to release print, that piece of film is 70mm wide. Better resolution, film grain less obvious in relation to picture elements.

Mike Todd (Todd-A-O) intro'd it some time ago. It was for selling, and exhibiting to best advantage, a big picture (Around the World in 80 Days with David Niven, I believe) sold in what then was called a 'Roadshow Engagement'. That meant there was an Intermission, musical preludes to both 'acts', and assigned seats, like a play.

It's fallen out of fashion for some time; most audiences haven't heard of it.

Answer 4

This question comes up pretty much once every two or three years, because of one man: Christopher Nolan. He's developed a bit of a brand of producing these bigger-than-life movies and a huge advocate of audiences seeing them on the biggest possible screen imaginable, and of course in 70mm IMAX.

To the devout, anything less is ananthema.

As an industry professional and member of the "exhibition" community (as movie theater operators are known in the industry), I love that Nolan is such a vocal champion of the cinematic experience. Hearing him speak and present Oppenheimer at CinemaCon reminded me why we do what we do.

At the same time, I don't agree with the over-emphasis placed on the 70mm format. With respect to Mr. Nolan, who is by every standard a master at his craft, there is much more to exhibition than the size of the film stock, and these are important considerations that help form the quality of the viewer's experience in many meaningful ways. Convincing the general public that they are not getting the whole experience unless they see it in 70mm discourages people from going, especially when such presentations are very rare.

What is better about 70mm?

As others have correctly pointed out, 70mm contains significantly more picture information than any other standard format is capable of containing. That's great, but the real question is, can you see this? Perception is reality, and human biology is a much bigger limiting factor than the number of pixels in the projected image. Also, film doesn't have pixels, so it's not exactly a useful comparison in the first place.

If you look carefully, even in a 4k cinema, you'll be able to see pixelation, especially in non-natural shapes like text. It is barely noticeable, and you have to look for it, but it's there. On film, this is not a problem. So, is this the end of the discussion? Hardly. The moment the image moves, the pixelation is gone - lost to the many signal processing techniques our brains have developed to compensate for the various limitations in the biology of the eyes.

So, if we allow that a 70mm image contains more visual data, then does that mean that 70mm is objectively a better format to watch a movie? There are many reasons why it might not be, all of them practical, and all of them more important to quality than the number of pixels on the screen.

Additional Picture Quality Factors

Resolution is one of many measures of picture quality. Others include brightness, contrast, stability, illumination uniformity, and color range and accuracy. It should not surprise anyone to know that there are SMPTE standards governing all of these aspects and more. As exhibitors, we calibrate our theaters, big and small, to these standards. IMAX and Dolby Cinema, among other premium formats, have expensive technology to exceed these standards.

Digital cinema projectors were specifically designed to meet these standards with much greater consistency than film projection equipment, and with low or no training required from the cinema's staff. This is huge, because it helps ensure that digital presentations of all varieties run better and produce a significantly better product than the average film presentation.

Overall, film really can't compete with digital in these areas. You're going to get higher color accuracy, better (perfect) stability, excellent illumination uniformity, and better brightness with a digital presentation. All of this is due to the stubborn laws of physics and how a digital image is produced.

Additionally, film degrades significantly as it's run. Even after one day of showings, a film print will accumulate dust and scratches. By the end of the run, it is quite common for a film print to be unusable due to the accumulation of damage. And this damage is much easier to see than pixels on a 4k digital image. The size of the 70-foot Imax screen makes it even easier to spot these issues.

Other Quality Factors

We've so far failed to discuss one half of the cinematic experience, and that is the audio presentation. Thankfully, we don't see Mr. Nolan out there extolling the virtues of optical stereo. We can all be thankful that uncompressed digital audio is the standard for all digital cinema presentations. 70mm Imax also uses a digital soundtrack provided on optical media.

And, while Imax theaters are particularly known for their sound systems as well as the large screens, Dolby is another company that has operated in the cinema sound space for decades. Their audio formats, including Dolby Atmos, contain more channels and more stringent calibration requirements than Imax. Having regularly attended movies presented in both formats, it is my opinion that Dolby is the superior format at present.

In Summary

Should you endeavor to see Oppenheimer (or any other movie) in 70mm Imax, as the director recommends? I would say no. Instead, I would recommend seeking out a regular digital Imax, or even better, a Dolby Cinema for the best premium experience. The next best thing would be to seek out a premiere house at a good theater near you. You can tell which these are because they typically have at least 15 or 20 seats across in a recliner configuration. I would avoid theaters without recliners.

Ultimately, a moviegoer looking for a memorable and high-quality experience as Christopher Nolan intended doesn't have to attend a 70mm presentation to get one, nor is it necessary to shell out upwards of $20 for a premium ticket. With today's digital presentations, there is a lot higher quality than with film even in a regular auditorium.