35mm film was invented in 1890 and shortly went on to become the industry standard. It can provide aspect ratios ranging from 1.33 to 2.65 for everything ranging from TV to Cinerama feature films. In this article I will attempt to explain different 35mm formats and aspect ratios and how they are achieved using 35mm film. Aspect ratio is a measure of a pictures width divided by height. For instance a 16×9 widescreen TV has a aspect ratio of 1.78. Old style 4×3 TVs had a aspect ratio of 1.33 and widescreen Cinemascope movies are 2.35.
The standard pulldown for 35mm film is 4 perforations per frame which gives you 16 frames per foot. A second of film at 24 frames per second runs 1.5 feet and 1000′ of film provides about 11 minutes of running time. All 35mm projectors in theaters are 4 perf pulldown and run at 24fps. The format you shoot is determined by the gate and ground glass viewing screen used in the camera as well as how the film is projected or transferred to digital. I’ll explain this as we go through the formats. The following 35mm formats are available.
In the days of silent films there was no soundtrack on the film so the image was made as large as possible. Measuring about 24.89 x 18.66 mm the silent aperture went the whole with of the film from sprocket holes to sprocket holes and was 4 perfs high. It had a 1.33 aspect ratio. This was the only 35mm format until sound was introduced in 1929. This is now known as Super 35 or Full Gate.
When sound was introduced in 1929 space was needed for the optical soundtrack so the frame was made smaller and moved to the left to leave room for the soundtrack between the right side of the frame and the sprocket holes. The academy frame measures about 21.94 x 18.49mm and has a aspect ratio of 1.37. This had the added benefit of leaving enough space between frames to make a cement splice when cutting negative so academy film negative can be cut onto a single roll. This was the only aspect ratio from 1929 until the 1950s.
The 1950s was a decade of change for motion picture formats. Television was introduced and movie attendance dropped. The movie industry had to do something to make going to the movies exciting again. This included the widespread use of color film and several widescreen formats including Cinerama, 70mm, Vistavision and Cinemascope as well as 3D films and improved multichannel sound. Of these formats only cinemascope could be shown in a ordinary movie theater without major modifications.
The Cinemascope gate is the same width as the academy gate, about 21.94 mm but the height is increased to 18.49mm resulting in a aspect ratio of 1.18 and eliminating almost all the extra space between frames. Cinemascope is shot with anamorphic lenses that squeeze the image at a 2-1 ratio. These camera lenses squeeze a 2.35 aspect ratio image down to 1.18 on the film. Anamorphic projection lenses are used when showing Cinemascope movies to spread the image out to 2.35 on the screen. All theaters had to do to show cinemascope movies was get Cinemascope aperture plates and anamorphic lenses for their projectors and a 2.35 aspect ratio wide screen. Thousands of films were shot in Cinemascope and it is still used today. It is also sometimes called “Scope” or “Anamorphic”
For many decades Panavision had a virtual monopoly on high quality anamorphic lenses. These were in Panavision mount so they could only be used with Panavision cameras. That has changed today with anamorphic lenses available from Arri/Zeiss, Cooke, Hawk and others. They are very expensive to buy or rent, tend to be slower (smaller maximum aperture opening, requiring more light) and don’t focus as close as the equivalent spherical lenses. Anamorphic lenses can also introduce certain image distortions like wide blue horizontal lens flares and changes in shape when pulling focus. Many people like these and many of the Anamorphic lenses built for digital cameras incorporate these distortions. It should be noted that these Anamorphic lenses for digital production will not work on film cameras. To work on modern film cameras Anamorphic lenses need to have a 2x squeeze and a PL mount.
1.66, 1.85, 1.78
With the huge difference in width between 1.37 Academy and 2.35 Cinemascope many directors and DPs wanted something in between, so the 1,66 and 1.85 aspect ratios were introduced. 1.66 was mostly used in Europe, 1.85 in America. Shot with normal spherical lenses 1.66 and 1.85 were just Academy with the top and bottom cropped off. This could be done by shooting with a 1.66 or 1.85 gate and ground glass in which case 1.66 or 1.85 was all you would get on film. Often an academy gate was used and the crop happened in projection or film to tape transfer. This did leave the vertical framing up to the projectionist showing the film or the telecine operator doing the transfer which could result too much headroom with the possibility of boom mics or lights showing or too little headroom with heads cropped off. However it did give more flexibility in reframing for the 1.33 TVs used at the time.
Combo ground glasses provided frame lines for 2 different formats. For some projects that were intended for both theatrical release in 1.85 and TV release in 1.33 an academy gate and 1,33 / 1.85 combo ground glass with a common topline was used to keep the headroom consistent for both formats. Now that TVs are 1.78 aspect ratio (very close to 1.85) this is no longer done. 1.78 ground glasses are available that can be used with a Academy or 1.66 gate.
If you are shooting a format that will be cropped in post be sure to shoot a framing chart carefully lined up with the frame lines you are using at the head of your first camera roll so the telecine operator or editor can properly frame the shot and black out what you don’t want.
Super 35 goes back to the old full gate or silent aperture to give you the largest image on film. The full Super 35 gate is 1.33 aspect ratio but other Super 35 gates are available. Not intended as a projection format as there is no place to put the optical soundtrack, Super 35 movies are usually shot with a 1.78, 1.85 or 2.35 ground glass and optically or digitally converted for projection. Many Super 35 films shot in 2.35 were optically converted to 35mm Anamorphic or 70mm for projection. Sometimes a common top line was used if shooting for multiple formats. Over 1000 movies have been shot in Super 35 including Titanic, Terminator 2, Backdraft and Gladiator. It has the advantage of letting you use faster and less expensive spherical lenses. It is also a excellent format to shoot for digital transfer as it provides the largest picture area of standard 35mm formats. As with 1.66 and 1.85 be sure to shoot a framing chart at the head of the first roll to show the telecine operator your framing.
35mm Formats Requiring Special Cameras
3 Perf Super 35
When shooting Super 35 and framing for 1.78, 1.85 or 2.35 there is quite a lot of unused space between frames. 3 perf Super 35 eliminates most of that space by changing the pulldown from 4 perfs per frame to 3. This requires a special camera with a 3 perf pulldown and gate. The 3 perf super 35 gate is 1.75 aspect ratio, perfect for 1.78 or can easily be cropped to 1.85 or 2.35. Most of the major 35mm sync sound cameras are available in 3 perf versions though these can be hard to find. The big advantage to 3 perf is a 25% increase in running time per roll with a 1000′ roll of film giving you about 14 minutes instead of 11 minutes for 4 perf. This can result in a 25% savings on film stock and processing costs, digital transfer too if you pay by the foot but not if you pay by the hour. Because the 1,78, 1.85 or 2.35 frame is the same size as 4 perf Super 35 the quality is just as good.
The disadvantages of 3 perf Super 35 is that it cannot be printed and projected on a 35mm projector unless you do a expensive digital intermediate or optical conversion to 4 perf 35mm. This cost of this will usually more than make up for the 25% cost savings on film stock and processing. Also if you shot 1.78 or 1.85 aspect ratio and want to do a negative cut for a high resolution scan and archival purposes you will have to cut onto A and B rolls as there is not enough space between frames to make a cement splice. This requires black leader which is now discontinued, hard to find and expensive. However if you are finishing on digital only these disadvantages will not effect you.
2 Perf Techniscope
2 Perf Techniscope reduces the pulldown further to 2 perfs per frame. The Techniscope aperture is half the height of the Cinemascope frame without the squeeze. The gate is 2.35 aspect ratio and this is the only aspect ratio you can shoot with 2 perf cameras unless you want to crop the sides of the frame reducing the frame size and quality. This is the smallest frame of all 35mm formats and the quality isn’t as good as Super 35mm but is still very good. 2 perf Techniscope was used by Sergio Leone for all his westerns, and more recently for “The Fighter” and “the Place Beyond the Pines” Cameras are even harder to find than 3 perf but the running time of each camera roll is doubled with a 1000′ roll running 22 minutes. This results in a 50% savings in film stock and processing costs, digital transfer too if you pay by the foot but not if you pay by the hour.
Techniscope movies were always optically converted to Cinemascope for projection and if you want to make film prints for you still have to do this, or do it by digital intermediate. Either way you are looking at a big expense that would probably more than make up for any cost savings on film stock and processing. Also like 3 perf, if you want to do a negative cut you would have to cut onto A+B rolls using black leader, another substantial expense. Like 3 perf, to get the cost savings of shooting 2 perf Techniscope you have to finish only on digital.
Going from the smallest 35mm format to the largest, VistaVision runs the film horizontally through the camera with a pulldown of 8 perfs per frame and the frames arranged horizontally like 35mm still film. This results in a picture size of 24 x 36mm and a aspect ratio of 1.5. VistaVision was never intended as a projection format. It was invented by Paramount Pictures in 1954 as a high resolution film format from which regular 35mm and 70mm prints could be made. The much increased picture size resulted in less grain and sharper images on the final print. Usually the 1.5 aspect ratio was cropped to 1.66 or 1.85 for 35mm projection or 2.20 for 70mm projection. VistaVision negative had exceptional picture quality and resolution and could compete with 65mm, as many of the new digital transfers of VistaVision movies clearly show. Because of the 8 perf pulldown, running times for a 1000′ roll of film were reduced to 5 1/2 minutes but VistaVision had the advantage of being able to be processed and printed at any lab that could process 35mm.
Alfred Hitchcock really liked VistaVision and used it for To Catch a Thief, Vertigo, North by Northwest, The Man Who Knew too Much and The Trouble With Harry. It was also used to shoot, White Christmas, The Ten Commandments, The Searchers and Spartacus among others. By 1961 film stocks had improved and VistaVision fell out of favor, mostly due to it’s increased cost. It found new life in the 70s and 80s as a high resolution special effects format and was used for most of the effects shots on the original Star Wars and Back to the Future films among many others.
The most ambitious of the 35mm widescreen formats was Cinerama. Shot with a special camera that contained 3 lenses and 3 movements the Cinerama camera shot 3 rolls of film at the same time creating a combined 2.65 aspect ratio when the 3 panels were combined. The camera shot in a crisscross pattern using 27mm lenses with the right camera shooting the left image, the center camera shooting the center image and the left camera shooting the right image for a combined 146 degree view. Each image was 6 perfs in height and the width was the same as Super 35. Frame rate was increased to 26 fps. to reduce flicker. Cinerama films were projected the same way using 3 synchronized projectors on a giant curved screen in specially built or modified theaters. Sound was provided by a synchronized roll of 35mm magnetic film containing 7 tracks of high quality audio.
Cinerama was incredibly hard to shoot, edit and project. The cameras were very large and heavy, has no way to see the entire frame accurately and were very cumbersome to use. To see the framing for each camera the magazine had to be removed and a viewfinder attached to the back of each gate. There was a pretty inaccurate viewfinder on top for use while filming. To make matters worse you couldn’t change lenses and close ups were impossible. Because of the lenses crisscross pattern great care had to be taken with any shots in which anything crossed the frame or it might appear twice or distorted at seams. The fixed 146 degree view was very wide and hard to keep equipment out of. To make matters worse the camera was very noisy and had to be housed in a huge blimp for any sync sound shots. Total weight of camera and blimp was 800 lbs.
Editing the 3 panel films was equally difficult. Projecting the films required a minimum of 3 projectionists per show and specially equipped theaters. Although Cinerama films had very good resolution, the lines where the images came together were usually pretty obvious. Due to the frame rate difference and the difficulty of optically reducing the 3 panel image to standard 35mm it was generally impossible to make regular 35mm prints for standard theaters. On some films a separate camera crew would shoot the whole movie on a standard 35mm camera shooting Cinemascope alongside the Cinerama crew to make a version of the film that could be shown in regular theaters.
Cinerama was very popular and most major cities had a Cinerama equipped theater. However due to the many difficulties in production, editing and projection the format died out as a shooting format when 65mm film (Todd AO) was introduced. 65mm film was much easier to shoot and edit and the 70mm prints made from it were much easier to project and provided better quality without the lines between panels. Anamorphic 65mm provided a 2.76 aspect ratio, wider than Cinerama with all the advantages of being able to use one camera, normal editing techniques and one projector. In all 9 features were shot in true Cinerama including How the West was Won, Seven Wonders of the World, and South Seas Adventure. Several other films like 2001 a Space Odyssey were shot in 65mm but had the Cinerama logo and were shown in Cinerama theaters.
Almost all the Cinerama theaters are gone now or converted to digital projection. As far as I know only the Cinerama Dome in Hollywood can project true 3 panel Cinerama prints. If you ever get the chance to see one there by all means go.
3D movies also came out in the 50s and were very popular. They were mostly shot with a two camera rig with a mirror at a 45 degree angle and one camera shooting through the mirror and the other above looking down into it much as 3D digital productions are shot today. They had to be shown with 2 synchronized projectors projecting through polarizing filters with the audience wearing polarized glasses.
3D shared many of the same problems as Cinerama. The 3D camera rigs were huge, noisy and heavy, postproduction was very complex and very few theaters had the ability to project 3D. In theaters that could sometimes the sync between the 2 projectors was lost, ruining the show. A better solution was needed to make shooting and projecting 3D movies practical and in the early 80s Arriflex came up with one. They introduced a system called Arrivision 3D. This consisted of a set of 4 3D lenses in PL mount each having a left eye and right eye lens which transmitted the image through a series of prisms and lens elements inside to form two 2.35 aspect ratio images one above the other with the left eye view above the right eye view. These lenses could be used with any 35mm PL mount camera with a Cinemascope gate and ground glass. Looking through the viewfinder you would see two 2.35 images, one above the other. This made it possible to shoot 3D with one camera on one roll of film. Post production could proceed as normal and the film could be projected with one projector using a special Arrivision 3D projection lens that polarized and combined both images on the screen. The audience wore polarized glasses to view the film. There was no need to synchronize 2 projectors and any theater with a Arrivision 3D lens could now show 3D.
The most famous film shot in Arrivision 3D was Jaws 3 which was shot with an Arri 35BL-3 camera. Due to the small image size of Arrivision 3D (the same as 2 perf Techniscope) and the complex optics of the Arrivision 3D lenses, the image is not as sharp as regular 35mm but isn’t bad. The Jaws 3 Blu-Ray disc contains both the 2D and 3D versions of the film so you can judge it for yourself. Since I don’t have a 3D TV I can only see the 2D version. The special effects are probably the worst ever done but that is not the fault of the shooting format.