16mm, 35mm, and 70mm film gauges

In part one of this 2 part article, we looked at some common small gauge film formats to help you identify which material you are restoring. In this second part we move on up to the common variations of the industry standard 35mm film gauge, as well as a couple of common larger formats.

Just remember : )

Like part one of this article, with every example I will be using industry standard 35mm Academy 4 perf frame for a size comparison and whilst this isn’t a comprehensive list, it will provide you with a working knowledge of the most common film gauges you might come across in film restoration.

A bit about the 35mm format

The 35mm film gauge is the most common and possibly the oldest type you will likely come across. The first form of this popular film gauge was introduced in 1892 by #William Dickson and #Thomas Edison and went on to became the the accepted international standard for film projection in 1909 due to its size being a good trade off between quality and cost.

The film gauge has chemically undergone many changes since then including colour and a redesign to create a safer non volatile film base but physically, it has remained the same with only the 4 perforations on either side having had very minor alterations for different applications.

Despite the rise of digital cinema cameras and only a single manufacturer making motion picture film stock the 35mm film gauge is still in use today with many DOP’s and cinematographers still preferring the look. Being the industry standard, countless feature films and television programs have been shot on this film gauge and as such, it’s likely to be the most common format you work on as a digital restoration artist.

In its standard form 35mm film gauge has a maximum exposure area of 24.89mm by 18.67mm in a 1.33:1. However, the exact size of the exposure area varies depending on the given capture format and below i’m going to be describing the most common formats starting with, as the previous article, the smallest.

Main usage: feature films, modern broadcast, commercials

Developed and introduced by Technicolour in 1963 this wide format uses an exposure area of 21.95mm by 9.47mm in a 2.33:1 ratio.

While looking physically small in comparison to the full aperture 35mm format, #Techniscope had a some key advantages. Rather than using the standard 4 perforations in a negative pulldown, #Techniscope only uses 2 perforations which has the benefit of doubling the amount of frames you can expose on a given roll of film. Additionally, standard spherical lenses could be used which were more accessible and quite often faster, sharper and focused closer than the anamorphic equivalent and despite 4 perf with anamorphic lenses being the benchmark of the 35mm formats, 2 perf allegedly had more clarity when projected, perhaps down to the simpler optics.

A number of major films used the format to great success including The Ipcress File (United Artists 1965) which had a major restoration using PFClean. Unfortunately, the format itself never quite reached the same popularity as 4 perf as initially there was some criticism of the format due to additional complexities in editorial and printing despite these generally being resolved with the advent of the digital intermediate. It was also generally considered to be more grainy when compared to 4 perf due to the reduced size of the exposure area. Artefacts like gate hairs that would have been cropped out in other formats became a problem when restoring 2 perf.

Main usage: modern broadcast, feature films, commercial

Initially devised and patented in 1975 by Miklos Lente and called Trilent 35, this format offered an exposure area of 21.95mm by 13.9mm in a near 1.78:1 ratio, using a 3 perforation pulldown.

Initially there was no industry interest in this obscure gauge and it lay dormant till the early 1980s when cinematographer Rune Ericson collaborated with Panavision to breath new life into the format with the intention of initiating an industry change to convert all film equipment over to the format including projection systems in theatres.

As with the 2 perf Techniscope, there were advantages to using the now renamed 3 perf format. Due to the format using a 3 perforation pulldown the film ran through the camera 25% slower than 4 perf resulting in a reasonable saving to be had on film stock when shooting for non anamorphic widescreen ratios.

Also like Techniscope, 35mm 3 perf simply never acheived the popularity of 4 perf. Despite the savings in film stock, it came down to the fact that large numbers of equipment such as projectors and optical printers would need to be converted, which proved to be undesirable.

This didn’t stop people from using the format though as 3 perf could be transferred optically to 4 perf for release. Eventually these issues became irrelevant as the digital intermediate process removed many of these obstacles. High end television made good use of the format as it matched the ratio of HDTV’s whilst saving money on film stock.

35mm 4 perf Academy / 1.37:1 / 1.66:1 / 1.85:1

Main usage: modern broadcast, feature films, commercial

Having gone through a few variations since its initial conception in the early 1920’s, the Academy of Motion Picture Arts and Sciences in 1932 refined 4 perf to bring standardisation to the industry. The format later became known simply as ‘Academy’.

With an aspect ratio of 1.37:1 the camera aperture measures 21.95 mm by 16mm with the soundtrack area on the left side. All films shot between 1932 and 1952 used the Academy 1.37:1.

In the early 1950s Fox announced it’s up coming widescreen format cinemascope. This led to the other Studios looking for a ways to achieve similar wider ratios for non anamorphic (flat) presentations. Paramount in 1953 became the first to deviate from the standard 1.37:1 ratio with 1.66:1. This format was achieved by simply masking the top and and bottom of the 1.37:1 image.

While America favoured 1.85:1, it was Europe who eventually adopted the format for presentations shooting large numbers of film in this format. These productions were often photographed conventionally using the full 1.37:1 and cropped later on rather than using any in camera masking.

Universal Studios and Columbia Pictures were the first to utilise the 1.85:1 format and the ratio was achieved similarly to the way 1.66:1 was derived, by cropping the academy 1.37:1 frame at the top and bottom. This provided a way for the industry to provide a true widescreen ratio whilst keeping the costs down when modifying existing equipment. It also provided an easy way for films shot for 1.66:1 to be presented in 1.85:1 as the framing differences weren’t drastic. By the mid 1950’s 1.85:1 became the standard for non anamorphic theatrical presentation in American.

Right up until today the vast majority of non anamorphic features are still exhibited in the 1.85:1 ratio with countless features being shot in this format and recently there has been a small resurgence in the format for acquisition, a great example being Wes Anderson’s 2014 award winning The Grand Budapest Hotel.

Main usage: feature films, modern broadcast, commercial

The initial concept for Super 35 was to return to using the full aperture area of the 4 perf 35mm film which in essence is the same as Edison’s silent original from the early 1900’s.

The concept was to use the full area of the frame and then crop down to 2.35:1 and reduction print/blowdown to a 4 perf print with the theory being that the use of a larger area of the film when compared to the academy formats would provide increased fidelity and tighter grain. Confusingly, here is also a 3 perf version of super35

Super35 uses the full aperture area of 24.89mm by 18.67mm in 4 perf and 24,9mm by 14,7 mm in 3 perf. While I won’t be going into the various extraction areas (it can get hugely complex with some productions even opting to use custom framing), the most frequent terminology you will hear used are ‘common top’ and ‘centre cut’. These were provisions in framing to allow for a television versions to be made with the maximum amount of neg area, although nowadays it is much simpler with many films being displayed in the original aspect ratios.

In the pre-digital intermediate era, the format was a bit controversial among industry professionals. This was because many believed the steps required to optically print the extracted Super35 area to a 4 perf print softened the image and negated its benefits. However there were those who preferred the process and the ease of working with spherical lenses, James Cameron being a big proponent having shot a number of his films on the format.

When digital intermediate came about in the early 2000’s many of the issues using Super35 disappeared. With DI, Super35 could be scanned into the computer cropped to 2.39:1 and rendered to anamorphic 4 perf frame size without any generation loss at all. Additionally there were benefits to working in post with the the full uncropped area of Super35. Images could be easily re-racked and the extra information outside of the crop area benefited visual effects and proved a popular modern format with many films being shot on it.

Anamorphic 35mm ‘Scope’

Main usage: feature films, commercial.

While it has its origins in the early 1920’s and optically even before that in WW1, the major use of anamorphic in the film industry really began with the race to create wider aspect ratios for cinema presentation during the early 1950’s to compete against the increasing popularity of television. While other studios went down the road of matting the top and bottom of the 1.37:1 academy area to achieve a widescreen ratio it was 20th Century Fox who choose the anamorphic format naming it CinemaScope, and produced many films between 1953 and 1967 using the full aperture area of the 4 perf 35mm frame. With SMPTE and Panavision making changes and refinements to the format during that time, including slight changes in aspect ratio and the inclusion of an optical soundtrack area, it later became simply known as “Scope”.

Rather than projecting a spherical image onto the film plane, anamorphic optics project a horizontally compressed oval image in a 2x ratio or 2:1. When the film is processed and a print is made for projection another anamorphic lens with a matching 2:1 squeeze factor is used on the front of the projector to un-squeeze the image and present it in its correct ratio. For capture anamorphic uses nearly the full height of the 35mm 4 perf frame with an exposure area of 21.95mm by 18.6mm. The format was an ingenious way to maximise the negative area whilst delivering a very wide aspect ratio of 2.39:1 and still using the same film stock, cameras and projection.

Anamorphic is an interesting format which has seen a resurgence in recent years with many directors such as J.J. Abrams and Christopher Nolan opting to use the format, keen to capture the classic cinematic look for modern presentation. Due to the fact that the format uses much more of the 35mm negs surface area, approximately 408 mm², grain structure is much tighter when compared to other 35mm formats with the same presentation ratio. Due to complex optics, flaring is common and quite often there is fall off and softness towards the edges of the frame, especially on older films. Whilst these aren’t usually problems you would want to remove during the digital restoration process they can make the process much more difficult.

VistaVision

Main usage: feature films, visual effects

VistaVision was first created by Paramount Pictures back in 1954. Often referred to as lazy 8, on account that the film travels horizontally through the gate very similar to the 135 still photography format which uses 8 perforations top and bottom per exposed frame, the primary purpose of the format was to create a finer-grained print for widescreen 1.66:1 presentations. With an exposure area measuring a massive 37.39mm by 25.3mm it was a major step up in quality vs the traditional 4 perf Academy format.

Despite a large number of feature films being shot in the format, Paramount discontinued it less than a decade after they introduced it, mainly due to the fact there had been significant advances in film stocks which negated the benefits of the format. Vistavision was, however, still used in other countries such as Japan right up until the late 1980s. That wasn’t the end for VistaVision though.

Cheaper than 65mm, combined with modern finer grain film stocks and with the increased stability of the 8 perf mechanism, VistaVision became the go to format for many visual effects productions. The advantages of the format became very apparent when optical printing and VFX companies like Industrial light and magic revived the format, using it extensively in their motion control systems to photograph effects models for the Star Wars films. Today, Vistavision’s use in visual effects is still in evidence right up until 2014 when Christopher Nolan used it for his feature film Interstellar.

Ideas from VistaVision eventually evolved into the IMAX 70mm format which uses a similar horizontal film feed and the format lives on in digital form with modern high resolution digital cinema cameras using a VistaVision sized sensor.

65MM, 5 perf

Main usage: feature films, visual effects

The 65/70mm film gauge has been around since the very early days of the film industry but it was producer Mike Todd in the early 1950’s who should be credited with popularising the format again. Called the Todd-AO process it was developed as a competing system to Cinerama which at the time was hugely complex and expensive system.

This film format used two separate film stocks; 65mm to capture the images during production and 70mm print used for distribution in the theatres. With perforations lining up on both gauge sizes, the extra 5mm on the 70mm is used for optical soundtracks.

Panavision adopted the format after Mike Todd’s death in 1958 creating their own slight variations Super Panavision and Ultra Panavision 70. Both of these variations are mechanically compatible with the original format, with Ultra 70 being a 1.25x anamorphic system which created an extremely wide aspect ratio. Quentin Tarantino used Ultra Panavision 70 for his 2015 film The Hateful Eight.

The 65mm camera neg uses an extremely large camera aperture of 52.48mm by 23.01mm which far surpasses the quality of even the largest 35mm format. 65mm using 1207mm² of exposure area Vs 35mm anamorphics 408mm². The quality on screen was unmatched and was only surpassed by the specialist 15 perf 70mm IMAX format in recent years. However the cost of shooting in 65mm was extremely high and it was reserved for use on only the highest budget films.

There were plenty of 70mm prints made especially from 35mm anamorphic blowups, which took advantage of the higher quality presentation format and the better quality sound. While a print is not the ideal starting point for a restoration, 70mm does offer vastly superior quality to a conventional 35mm print. Additionally the format was used for optical effects work to increase fidelity and reduce the amount of grain in the final images when optically printing.

Iconic films like 2001: A Space Odyssey (1968) have been shot entirely on 65mm, 1992’s Baraka being a stunning example of what the format is capable of. More recently Christopher Nolan shot large segments of Dunkirk (2017) using 65mm with key sequences being shot with the larger IMAX format. When scanned at a comparable resolution to 35mm the grain structure is extremely tight and the fidelity is extremely high. Having a larger area of film can have the potential for more surface dirt and issues but generally being such a high end format, camera original 65mm film elements are extremely well looked after.

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References: Hands on Manual for Cinematographers By David Samuelson