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Tech Tip	Subject
#1	Charging Batteries
#2	Aspect Ratios and Formats
#3	Shooting for HD
#4	3-Perf Tech Tip

Tech Tip #2

Aspect Ratios and Formats—Super 35 TV

Introduction:

This is the first of a series of tech-tips that endeavors to demystify aspect ratios/formats commonly, and some not so commonly used in 16 and 35 mm film production. There are many reasons why film formats are misunderstood by newcomers and professionals alike. Looking over the vast array of information published for the film industry there are many sources where one can find format specifications. However, there are relatively few references that outline the reasons involved in their development. It also seems odd that few comparisons among formats exist to aid those in such a visual medium. This series will hopefully bridge some of these gaps and assist in making more informed decisions with regard to the choice and use of formats.

The acceptance and standardization of various formats over the years has allowed for greater understanding and more efficient application. This is true on the part of individuals in the film community and among film equipment manufacturers. Unfortunately, newly introduced formats do not garner these traits. To add to this initial ambiguity, the Super TV format in existence since 1984 is predicated on the well established standard Regular 35 TV (1.33) aspect ratio. Many incorrect assumptions about the Super TV format have resulted. Because of the fore mentioned factors and recent popularity of Super TV we have opted to present it first in the series. We have compiled and organized specific information we thought pertinent to the proper use of the Super 35 mm TV format in the field.

Glossary of terms:

In order to discus the subject of Super 35 TV in depth, a list of relevant terms and their definitions are provided below:

Academy 1.37:1

• The aspect ratio created after the introduction of sound tracks to film. It maximizes the remaining area of the film more efficiently than 1.33:1, while allowing space for the presence of a soundtrack.

ANSI

• American National Standards Institute. A United States standards organization which oversees procedures and specifications for a variety of industries.

Aspect ratio

• The width to height proportion of the film frame; it is usually stated as one unit denoting its height by the number of units which make up its width e.g. 1.85: 1.
  

DIN

• Deutches Institut für Normung. German Standards Institute. An organization which oversees industry procedures and specifications for a variety of industries.

Extended viewing space

• The area of a ground glass which extends beyond the format lines and may exceed the actual film negative area. Used to assist the operator in following action in and out of the frame.

Format area

• The actual height of the image multiplied by the width, in inches or millimeters.

Keystone (Keystoning)

• The effect that occurs to an image of a flat object when the camera or the object are not parallel to the film plane. Perceived as one side of an image appearing larger or smaller than its opposite side.
  

 Lens coverage

• The circular area formed by the cone of light created by the lens. The adequate or correct coverage of a lens should fully encompass the area bounded by the dimensions of the desired aspect ratio format being used. The diagram below shows the entire image capture area as it relates to the desired aspect ratio format.
  

 Silent

• Introduced in 1895, it is the original format gate or aperture developed prior to the advent of sound tracks on film.
  

 SMPTE

• Society of Motion Picture and Television Engineers. A United States standards organization which oversees industry procedures and specifications.

 Super 35 mm

• The alignment of camera and lens that allows for the use of the area once reserved for the soundtrack. Super 35 centers the aspect ratio to the full aperture of the camera, thus allowing for a larger aspect ratio area along with an increased useable film area.

 TV(Standard 35 TV, Normal 35 TV, Regular 35 TV)

• An aspect ratio with a dimension of 1 unit high by 1.33 units wide. Its ratio is synonymous with that of a standard television screen.

 TV Safe Action

• Refers to the frame lines that exist inside the TV Transmission lines. Framing to these lines insures that what is within the frame is certain to be seen once the image is broadcasted to the viewer. SMPTE has set the standard measurements for Regular 35, however there is no consensus with regard to Super 35 TV.

 TV Title Safe

• Refers to the frame lines that exist inside the TV Safe Action lines. Used as a guide for framing titles. SMPTE has set the standard measurements for Regular 35, however there is no consensus with regard to Super 35 TV.

 TV Transmission

• The entire image area that is broadcast to television receivers. The outer areas of the image may or may not be seen once the video transmission reaches the viewer. Exists in both Standard and Super formats.

 Regular 35 mm

• The standard alignment of cameras and lenses in which the center of the frame is displaced to one side of the film aperture to allow space for the sound track.
  

 Universal negative area

• The entire exposed image area. From it are extracted all the specific aspect ratios.

 Vignetting

• The condition that occurs when lens coverage is insufficient for a given format. The effect is usually perceived as image with one or more corners shaded or cropped.
  
• Vignetted Image:
  
• Image with proper coverage:
  

Defining Super 35 TV

In regard to motion picture cameras, the term Super 35 refers to the physical manipulation of the camera in order to re-center the image as it is photographed onto the film. This allows the captured image to utilize that portion of the film once reserved for soundtrack.TVrefers to the way the actual image is framed for presentation on a traditional (non-HDTV) television. This aspect ratio isusually 1:1.33.

 The Advantage of using the Super TV Format

The Super 35 mm TV format has recently become very popular in television production. Its acceptance is due mainly to improved image quality; specifically a reduction of grain in the final print. Because there is no soundtrack, the super format allows for an image to be photographed onto a larger surface area. This efficiency means a greater number of granules that make up the image which translates into a less grainy transferred image. This presents the user with increased control over the image. For example, the user may opt to use higher speed, traditionally grainier film stocks without sacrificing image quality, or a scene might be reframed tighter in post production with little increase in grain.

Points of confusion

Like all TV formats (non HD), Super TV is one (1 unit) high by one and a third (1.33 units) wide. This may seem a simple point, but regardless of its size, the aspect ratio remains the same; it is the format area that changes from Standard 35 TV format to the various Super 35 TV formats. For example , Regular 35mm TV Safe Action as defined by SMPTE has an overall format area of 246.16 mm, compared with the format area of Super 35 TVSafe Action as defined by ANSI which has a format area of 380.25 mm. In terms of usable negative area, this is an increase of about 54%.

Although SMPTE has set measurement standards for Regular 35 TV, as of yet that consideration has not been extended to Super 35.

Adding to the confusion, multipleSuper 35 TV formats exist among camera manufacturers as well as standards organizations like DIN and ANSI.

Lens constraints for the Super 35 TV format

Now that we have discussed the basic conditions created by the enlarged negative area of the Super 35 format we will add another factor to the equation.

Lens coverage is an important factor to consider when shooting in any super 35 format. It is, however, the most critical in Super TV since thisformat requires the most negative area of any of the more rectangular formats i.e. 1.66, 1.78, and 1.85.

Because the width of any format is constrained by the constant distance between the sprocket holes, the height of the format remains the only dimension that can be altered to obtain a different aspect ratio that utilizes the maximum area of the negative. The consequence of a lens' failure to adequately cover the enlarged area of any format is called vignetting.

 

The above illustration shows how the Super TVformat can be affected by poor lens coverage while those of 1.66, 1.78 and 1.85 may not. Depending on the lens and the format used, vignetting may appear on the negative as a darkening or softening around some or all of the corners on the exposed film area.

It is important to note that simply looking through the viewfinder of a camera is not necessarily an accurate indicator of proper lens coverage.

 

 

The lack of standardization causes problems of format conformability

 

The most confounding issue regarding the Super TVformatis the lack of standardization. In most instances it is easier and more desirable to use conventional or universally accepted film formats. The reason is that their exact linear dimensions (width to height ratio) are committed as a universally accepted standard among international standards organizations, camera manufactures and the film community. Standardization allows for the least confusion in the corresponding phases of production, post-production and exhibition. Since there is no conformity with regard to the Super TVformat, it is important when commencing a Super TVproduction to ascertain the exact height and width measurements of the specific variety of ground glass to be used in the camera. This information will be invaluable in choosing appropriate lenses for the format in question. Adequate lens coverage is the key concern when evaluating various lens types. Remember, the Super TV format is the most susceptible to vignetting. Correspondingly, the larger the format area, the greater the risk of vignetting.

There are three Super 35 mm TV formats that have not been used in the making of this comparative chart. Since there is no conformity among manufactures we thought it too confusing to include them in the above chart. However, they are important to mention in order to alert the user of their existence and the problems they may present when using different cameras or trying to achieve certain effects. In all cases, these ground glasses were designed to utilize the maximum amount of useable film negative. They are:

• Big TV Transmission and Safe Action
• Large TV Transmission and Safe Action
• Giant TV Transmission

As with all Super 35 formats, it is critical to confirm that a given lens, especially a zoom lens, is able to cover these formats.

Much confusion has resulted because of the lack of standardization and the varied terminology. One rental facility’s Big TV may be another’s Large. One DP’s definition of Giant TV may not correspond with another’s.

Shooting a test to confirm lens coverage

It has already been shown how critical lens coverage is, especially when using super formats. The most definitive method to confirm adequate coverage of any format is to perform a film test. Shooting a film test requires the specific lenses in question, the formatted ground glass, a white card and marking tape.

Steps for shooting a lens test are:

• Set the camera on a tripod at a distance from the chart that will insure that the entire viewing area will be covered including the extended viewing area. The film plane and the white card should be completely parallel to prevent a key-stoning effect of the image photographed.
• Lock off camera securely to eliminate any variations in results.
• Using two people, one in front of the camera at the white card and a second looking through the viewfinder, tape mark the white card with format markings exactly mimicking those of the ground glass format. This should also include multiple markings on the ground glass that are frequently used in combination i.e. TV Safe Actionand TV Transmission. The chart should appear like a larger version of the ground glass.
• Meter the chart, calculate exposure, and shoot enough footage required for analysis. Traditional projection will need more footage than if viewed on a telecine.

Shoot a test for each lens in question at a variety of distances, particularly close focus and infinity. When testing zoom lenses be sure to zoom in and out slowly in order to identify all the points in the zoom scale. To record a more precise record you might want to slate the lens at each of the corresponding zoom marks.

Shooting a Ground Glass Format Leader

• Follow the above steps number 1 to 3.
• Ideally, choose a lens that falls in the 35mm through 50mm range. Meter chart, calculate exposure, and shoot about 10 feet.

Coordinating formats in post

The last piece in the puzzle of Super 35 TV format is the coordination between the production and post house. Even though it sounds ludicrous, the majority of film shot and delivered for transfer is sent without a formatted leader. Without a properly formatted leader the laboratory has no guidelines by which to extract the intended format area. In order to preserve the integrity of the intended image, it is essential that the assigned camera crew perform a test as outlined. Because of quality issues we advise not using leaders developed by laboratories, but rather a leader specific to the camera and ground glass being used.

Recommendations and warnings

It is highly recommended that when using any lens in the Super format that the coverage of the film plane behind the lens and any possibility of vignetting in front of the lens be thoroughly checked prior to filming. Be sure to understand what the markings represent i.e. specific aspect ratio and linear measurements. Usually rental houses will know their gear and can answer any questions you have concerning the lenses and ground glasses they carry.

If you are mixing gear from different sources you may need to contact the camera and lens manufacturers. If you are still in doubt shoot a test.

Additional information

• ANSI, American National Standards Institute (www.ansi.org)
• Arriflex (www.arri.com)
• DIN, The German Industrial Norm Institute (www.din.ch)
• ISO, The International Standards Organization (ww.iso.ch)
• S.M.P.T.E, The Society of Motion Picture and Television Engineers ( www.smpte.com)

 

Dimensions were furnished by Arriflex.

 

© 2004 Schumacher Camera, All Rights Reserved.