Formats, Fields and Standards
by Mark Woods


I recently shot a Super 35mm film in Europe. During the prep, we shot a frame leader. (A frame leader is a shot of a chart that matches the frame edge as indicated on the camera's ground glass.) I rarely do this when I shoot in 1.85:1 or 1.66:1, and never for TV commercials. My thought has been that industry standards exist, and if I use properly maintained equipment from reputable rental houses, my images should drop into the frame they way I photographed them. Little did I realize the complications that exist in Super 35, a non-standard format; and little did I realize that when production misplaced the frame leader we shot in Europe, ensuing problems would be encountered by the postproduction supervisor at the optical houses. By moving through the idiosyncrasies of Super 35, I will explore some of the other formats, and point out some potential "opportunities" (i.e., problems) a cinematographer should be aware of.

2.35:1 Equals 2.40:1 Equals 2.39:1

First I would like to address the true 35mm anamorphic format, where the camera's objective lens is anamorphic. In this industry, you would think that most aspects are standardized if only because standardization will ultimately make things easier, more predictable, and save money for the producers. For example, it doesn't matter what ratio you call 35mm anamorphic lenses since they all equally affect the squeeze of the image. In the beginning, the format using 35mm anamorphic lenses were referred to as 2.35:1 (or simply, 2.35). SMPTE decided quite a few years ago that this format as presented in the theatres was actually 2.40:1. Nothing had changed except what ratio it was called. In putting this article together, I spoke with a number of people including my friend Tak Miyagishima at Panavision. I asked him if three cameras shot the same scene at the same time, one with a Primo 2.40:1 anamorphic, one with a 2.35:1 Zeiss lens, and the other with a 2.39:1 Todd/AO anamorphic, would there be any difference in the squeeze? Tak said they were all the same. Only the inherent differences in the lenses' designs and performance would be noticed. So if you refer to the anamorphic format with any one of these terms, you will be correct. Finally, the thing to keep in mind is that the squeeze is constant no matter which format you're talking about.

How does a 2X Squeeze Equal 2.40:1?

All 35mm anamorphic lenses squeeze the image 2:1. What that means is, if you look through the camera's optics at your star or starlet, and the image isn't unsqueezed, you see an image that has a major astigmatism and looks like something like a Modigliani painting. The scene through the lens appears to be twice as high as it is wide, or the converse, half as wide as it is high. What the numbers on each side of the colon represent is the relationship of the width to height of the frame in the theatre. So the squeeze is constant in the camera and in projection, only the proscenium changes.

What's so super about Super 35?

Super 35 is an anamorphic format filmed with spherical lenses. This image is composed side to side on the full aperture. The different ground glasses utilize different parts of the vertical area of the aperture. Take a moment to look at Clairmont Camera's ground glass diagram labeled Super 35 Centered on Full ground glass. The 2.4:1 format is indicated in the center of the full aperture, which includes the sound track area. The final 2:1 squeeze for the theatrical release is accomplished optically from the IP to the dupe negative. (A side note about this step. My friend Rob Hummel told me from his own experience that if the squeeze were put on the IP instead of from the IP, the quality would be much better. I checked this out at Foto-Kem, and they agreed that the quality would probably be better, but they currently don't have printers capable of performing this operation.) All dupe negs are generated optically from the IP. As you can see, the Super 35 format is actually an anamorphic format shot with spherical lenses. By the way, the term "Super" in front of any format indicates that the full aperture is being used (or more in the case of Super 16mm). Again, if you look at ground glass with Super 1.85, Super 35, and Super TV all centered on full (aperture) you will see how the full aperture is utilized. Compare this ground glass to the 2.35 Anamorphic Centered on Academy ground glass. You will see the space left for the sound track. The optical houses' field charts are of little use to us now, since they only indicate the size of the final image for theatrical presentation, not the final position on the film. Look at Pacific Title's 1.33:1 field chart with 1.85:1, 1.66:1, and 1.75:1 (1.78:1) all indicated with a common optical center. This is important to note. Elements with a common optical center shift the top and bottom of the frame equally. Shots with a common top shift only the bottom of the frame. You can see this difference on the Super 35 Common Top with 70mm and 1.85:1 also indicated.

These charts would be used to set up the optical printer for elements for the IP, in the pre-squeeze stage. This is also the field chart the optical house would use to place the top of the frame as indicated with a frame leader. They would note the settings on the optical printer and use them as a starting point for all opticals being done on the production. Finally look at the "Abyss Format" ground glass. Super 1.33, Super 1.66, and Super 1.85 are all centered of the full aperture, while Super 2.2 and Super 35 share a common top line with Super 1.85. This is an ultimate effort to protect the composition for all formats. I'm sure you are aware that Titanic was filmed in Super 35, and helmed by the same director as The Abyss, James Cameron.

All 12 Fields Aren't Equal!

Part of what I intended to accomplish in this article was to relate different formats to a 1.33:1 field chart. I feel this is the most logical "Tabla Rasa" since it's the most common field chart in use. It's been standardized for many years, and each of the formats I discuss can be placed somewhere on the chart and be fairly accurate. A 12 field for 1.33:1 is 12" wide and 9" high. By definition, all 12 fields are 12" wide (East/West). The difference in formats determines the different size of the increments in each field North/South. For example, the increment between an 11 field and a 12 field East/West, is .500". The incremental difference North/South on our 1.33:1 chart is .375". As you can see on the field chart provided by Pacific Title's Chris Bushman, the following formats 1.33:1, 1.66:1, 1.75:1 (1.78:1), and 1.85:1 can be referenced on the same field chart. The simple explanation for this is that the formats are created with mattes on the projector, or, in some instances, hard mattes in the camera. This field chart shows formats that share a common optical center-and not a common top. All of this is based on a 1.33:1, or TV aperture. Now take a look at the Super 35 Common Top Line Field Chart. If you notice, the increments North and South are smaller, even though this is a 12 field chart, and the 12 field indicators North/South stop at the edge of the 2.40:1 format's bottom. The reason is simple, the ratio is different, and therefore the increments are different, and smaller. The field indicators can't exceed the bottom edge of the frame, i.e. indicate a 13th filed, since a 13th field would be out of frame. The 12 fields define the total area of the frame. This is the case if the 12 field chart were based on 1.85:1. There would be no field indicators below or above the edge of the 1.85 frame. Since the sides remain a constant, each field side to side is .500" (1/2") apart. The different formats are reflected in different incremental vertical measurements. Again, these field indicators don't exceed 12 fields. This doesn't seem to be much of a problem, but in shooting Super 35 with a common top line, the vertical increments are different for each format. Of course you can try to compose a shot for all formats, but that doesn't really work. In postproduction the situation continues to become more involved. What if a director of photography shoots the negative in Super 35 for an anamorphic release? Later, for whatever reason, the producer decides to release in 1.85:1. Suddenly there's a great deal more information on the bottom of the frame. Also, if any zooms were done, and the camera's optics were centered to the 2.40:1 squeeze format, they would be off center and appear eccentric.

What if a production was shot in anamorphic 35mm for a blow up to 70mm? You would think that everything should fit, but it doesn't since the formats don't match exactly. The edges of the original 35mm image are cropped slightly to center the image vertically. As you can see, when you enter the anamorphic world, things aren't what they appear to be, and the edge of the frame isn't where you think it is when you blow up to 70mm or reduce to 35mm from 70mm. This has been a problem for some pictures shot in anamorphic 35mm and released on 70mm. If the director wants to use the whole frame, side to side, when shooting in anamorphic 35mm, something's going to be lost on the blow-up. This happened to George Lucas in Indiana Jones and the Temple of Doom.




Production Reality and Post Production Costs

I know of a production that used two supposedly compatible Super 35 ground glasses on two different cameras. One camera had a ground glass similar to Clairmont Camera's Bird on a Wire ground glass. The other camera had a ground glass much like Clairmont's Abyss format. These two ground glasses appear to be exactly the same, but aren't totally compatible. If the director of photography had the ground glass format specs laid out the way they're presented here, it would be obvious to him. One of the keys to look for is the vertical offset. On the Abyss ground glass it's .054, while the offset for the Bird ground glass is .063. This doesn't seem like much, but it's about 1 foot on a 60 foot wide screen. While these two ground glasses are fairly close, and it may not make much difference in a given shot, you can imagine the problems you'd encounter with ground glasses substantially different. A shot in this picture was composed correctly for the ground glass it had, but which one was it? And which ground glass would the postproduction supervisor indicate to the optical houses to use. On this project, the postproduction supervisor had to do 75 opticals to reposition the frames, partially because of the different ground glasses.

Now on to a bigger problem, a friend of mine familiar with Super 35 problems told me about a film that had a number of cameras set up with a Super 35 common top. On a couple of big action days, 8 cameras were added to the production. Unfortunately, these cameras came with the Super 35 ground glasses all centered on full aperture. There was no vertical offset! This offset is about 4 feet on the same 60 foot wide screen. You can imagine the number of opticals necessary to reposition the image and correct this mistake. Who was to blame? The director of photography is responsible for the picture, formats, and selection of ground glasses. Whoever prepped the cameras needed to be made aware of the ground glasses being used on the production, and the problems that are caused if they don't match, and this is the director of photography's responsibility.

Super 35 & Standards

I think you understand now that Super 35 is a non-standard format, and are beginning to realize what that means. As you can see with the various ground glass formats Clairmont has provided, the commonality of them all is the full aperture indicator. If a frame leader were shot with the full aperture indicated, and the frame lines of preference, then all cameras could be checked against this master chart. If the lines match, then the frames should also match. This might be a simple solution for the multiple camera scenarios, and an assistant prepping other cameras could check the ground glasses in the bodies with the master chart. It isn't practical for each camera to film a frame leader. Besides, who is going to compare the images, and how is the optical house going to know which camera shot which image? No; the camera department needs to standardize itself in this non-standard Super 35 environment.

By the way, there may be both horizontal and vertical offsets to place the optical center of the lens in the center of the image area as indicated by the ground glass. With this in mind, you can see the need for production to rent from reputable rental houses that are able to offset the lens ports of the different cameras in a consistent and precise manner. Also, problems might arise with sub-rentals where only the ground glass is changed and not the lens ports. With zoom lenses, this can cause a major headache beyond the offset of zooms during the shot. The lens may not cover the image area and vignette slightly, where you might not see it until dailies. You can imagine how that could ruin your day.

Some Final Thoughts

With all the things to think about when choosing to film in Super 35, there are always other choices, 1.85:1, 1.66:1, or anamorphic for theatrical release. In television, the producers are making the decisions, sometimes with little background or knowledge about the potential problems. You might take a moment to look at the Paramount Format. It seems to solve many problems, but it's a problem itself since it's another format using Super 35. Panavision has also responded to directors of photography and created their version of common top line. In the past, there were some efforts to standardize this format, but they collapsed. With the changes in DTV and possibly HDTV coming, there is a lot of scurrying to cover all format possibilities. There is even a "K" frame idea being floated now where an image would be shot with a compromise side indicated halfway between 1.78:1 and 1.33:1. The resulting image would be slightly squeezed for broadcast on NTSC TV, and would be slighting expanded for HDTV broadcast. That would solve our format problems! I'm not sure what the actors would say about being broadcast in HDTV expanded. I could see this being a problem for the cast of ER, or the cast of any other high profile program.

But, it's an exciting time in which we live. Shoot in Super 35, make wonderful images. Just be careful and consistent in your approach so the images you film make it to the screen in a smooth and professional manner. Be careful and know the problems since you can't rely on SMPTE, the labs, or even the camera manufacturers for guidance. When you use a non-standard format, you define the parameters. Just think through what you want to accomplish and how to go about it. I'd hoped that when I started this article, I would be able to provide an indication on the 1.33 Field Chart for the different formats. For example, the Common Top Line on the Super 35 Field Chart is also the 1.85 top line in the 1.33 Field Chart. At this point I don't think it's wise to approach opticals in this manner. A 1.33 Field Chart could be modified with the help of a frame leader filmed by the director of photography on the production. In fact, shoot, and protect, that frame leader shot from a master chart indicating full aperture and the frame lines you're using. Then match that chart to every camera's ground glass you use. That is only protection you have that you images will line up and be consistent.