The MGM PANAVISION Enlarged-film System
|Read more at|
The 70mm Newsletter
|Written by: Douglas Shearer Date August 25, 1955||Date: 01.01.2012|
To Mr. Arthur Loew cc: Mr. E. J. Mannix
Subject MGM PANAVISION LARGE-FILM SYSTEM
From Douglas Shearer Date August 25, 1955
The following series of notes is intended to cover the majority of the points of discussion which have come up from time to time with respect to the MGM PANAVISION enlarged-film system.
- 1 -
As a first requirement, our system is designed to produce a 35mm CinemaScope version which will eliminate the present CinemaScope problems of focus and definition, unevenness of squeeze from the center to sides of picture, distortion of the shape of faces in closeups, the bending of architectural and horizon lines, and to reduce the amount of grain which is visible when pictures shot on 35mm negative are projected on large screens. At the same time, the system was designed with sufficient negative area to produce highest-quality release prints of a shape and size equal or greater than any of the other known or proposed large-film "road-show" systems. If desired, it also provides for super "road-show" prints with an aspect ratio as high as three to one for exceptional situations which can accommodate very large screens having a height to the limit of acceptability, under which condition additional spectacle is achieved by added width. The shape of the picture at a three to one ratio does not give the impression of being over-elongated on extremely large screens.
The negative areas of our system which are utilized to produce the various types of release prints will be listed in a separate table below.
- 2 -
To make our system universally adaptable as stated above and to utilize a negative film of greatest economy in width and linear speed through the camera consistent with accomplishing this purpose, a 65mm negative has been chosen having standard perforations with the incorporation of a mild anamorphic squeeze in the taking lens system. The amount of this squeeze is half the amount produced by our present 35mm CinemaScope lenses, namely the lateral dimensions of the set are squeezed side-ways 25% when they are imaged on the negative. The usual terminology used in this respect would be a squeeze of 1.33 to 1. (The standard CinemaScope lens squeezes the objects laterally 50% and is spoken of as a 2 to 1 squeeze.)
The mild 25% squeeze in our system is the means of avoiding optical problems with respect to definition and other distortions which are inherent when the 50% squeeze of standard CinemaScope is incorporated in the camera lenses. At the same time, our 25% anamorphosis regains some of the depth of focus lost in large-film systems where straight spherical lenses are utilized. Both the above features minimize the amount of set light necessary for acceptable depth of focus when large-film negative is used.
- 3 -
The standard frame speed of 24 per second is adopted since any other frame rate would not permit a system to be universally adaptable for the various release versions. Higher than standard frame speeds increase the amount of set lighting in proportion to the increase in speed. More important however, the 24-frame speed eliminates the necessity for shooting a dual version for the regular release of pictures with the attendant exorbitant expense.
- 4 -
The flicker or jitter present on large, bright exhibition screens during certain types of scenes in our standard CinemaScope exhibition can be eliminated by the use of three-bladed shutters on the projectors instead of by speeding up the frame-rate of the whole system.
A recent survey we have conducted throughout the principal circuits of the United States, including our own, indicates that in 90% of all theaters, sufficient power is available in the booths to produce adequate screen illumination when using a three-bladed shutter. It is assumed that adequate modern projection lamp equipment will be supplied for any situation where a "road-show" type exhibition on large positive film is warranted.
- 5 -
It should be born in mind that any system utilizing larger than standard negative requires the making of internegative facilities, or Technicolor facilities, or the development of a continuous-type optical printer to produce prints other than the size and shape of the original negative. This applies equally to our system, Todd AO, VistaVision, or the Fox large-film system.
|More in 70mm reading:|
The Importance of Panavision
Ultra Panavision 70 - almost like a real story
MGM Camera 65 & Ultra Panavision 70
Panavision and the Resurrecting of Dinosaur Technology
|The manner of making release prints from our 65mm negative system are as follows:|
|PRINT TYPE REQUIRED||PRINTING METHOD|
| || |
|A. MGM PANAVISION, 3:1 ratio, 65 or 70 mm Super Roadshow||Contact 65 or 70mm prints|
|B. MGM PANAVISION, 2.5:1 ratio, 65 or 70 mm Roadshow||Contact 65 or 70 mm prints|
|C. MGM CINEMASCOPE, 2.5:1 regular release magnetic track, and 2.3:1 optical track ||35mm optical reduction internegative and contact prints, or Technicolor reduction matrix and IB Prints|
|D. TODD AO, 2.3:1 ratio, 65 or 70mm Roadshow||65 or 70mm optical step prints (24 frame rate only)|
|E. TODD AO, 2.5:1 ratio, 35 mm CinemaScope extraction ||Has not been demonstrated and no information as to availability of a printing lens for this purpose.|
|F. FOX, 2.5:1 ratio, 55mm Roadshow ||Optical step prints (this is similar to method Fox must use.)|
|G. VISTAVISION, 1.85:1 ratio, Widescreen 35mm regular re-release||Optical reduction internegative and contact prints or Technicolor re-duction matrix and IB prints. (This is similar to methods available to Paramount.)|
|H. VISTAVISION, 2:1 ratio, Lazy 8-hole 35mm Roadshow||Optical 8-hole step prints|
|I. VISTAVISION (Proposed), 2:1 ratio, Full-frame 1.7 squeeze 35mm||Optical internegative and contact prints or Technicolor IB prints (similar to methods Paramount must use).|
|J. CINERAMA, 2.7:1 ratio, Three-print projection (at 24 frames only)||Optical step prints|
| || || |
| || |
|There are two very important points in the above. First, we do not need to use the Fox, Todd AO or VistaVision taking system in order to release product through any theaters which they equip for their particular systems since we can make an equally good or better print from our negative onto their positive method if we wish to book into their road-show theaters. Second, the reverse of this situation is not true since the Todd AO, VistaVision, and Fox negative sizes and shapes and lens designs do not make prints universally as good for all the print systems.|
- 6 -
In order to make standard CinemaScope release product from spherical or unsqueezed original negative (such as Todd AO) it is necessary to introduce a 2 to 1 squeeze in a printer in the form of an internegative or a Technicolor matrix from which is then made standard CinemaScope contact or IB prints.
There is at present only one make of printing lens which has shown itself capable of doing this with adequate definition. This is a Panatar lens.
Since Todd AO claims to have a proprietary system, I seriously question whether Panavision will supply lenses for the purpose of producing CinemaScope versions from Todd AO negative. As a consequence, until Todd AO demonstrates that they have developed a high-quality printing lens for this purpose without infringing the Panavision patents, we could not afford to start a production with Todd AO equipment without a simultaneous CinemaScope version, even though the Todd AO film was shot at 24 frames.
- 7 -
With respect to the Fox taking system wherein they introduce a 2 to 1 anamorphotic squeeze in the taking camera lenses, it appears from the test film shown that many of the deficiencies of this high degree of squeeze in the form of focus problems and astigmatism have not been eliminated. The results so far achieved by our more moderate squeeze have eliminated these objections.
The Fox camera will be running film at 180 feet per minute. Our cameras will run film at 112½ feet per minute. Due to the greater forces developed in running the Fox film at this high rate of speed, their cameras will, in all probability, need to be more bulky and heavy with larger magazines than our cameras and would undoubtedly be more subject to breakdown.
- 8 -
The Bausch and Lomb lenses used in the Fox system are more bulky and heavier than the MGM PANAVISION lenses by several fold. The size and weight of production camera equipment should be kept to a minimum which is equally true with respect to the size of the magazines and the amount of film which must be carried on the location shooting.
The Fox taking system on 55mm negative with each frame eight sprocket holes high increases the negative area of the frame to four times the frame area of the standard CinemaScope 35mm negative. This is an exorbitantly large increase in negative area beyond that which is required to produce maximum definition and reduction of grain. Apart from 37% more negative film as compared to our 65mm, the Fox film runs at double the speed of 35mm film as compared to 25% more speed for our 65mm film.
It will thus be seen that the Fox system increases both the film cost and the camera problems far beyond that which is necessary for best results.
The quotation below is an excerpt from a paper presented to the Society of Motion Picture and Television Engineers at Chicago April 21, 1955 by G. C. Higgins, R. L. Lamberts, and R. A. Purdy of the Physics Division of the Research Laboratory of the Eastman Kodak Company:
"The increased magnification required to fill the larger screens now used in theaters has resulted in a noticeable decrease in definition. Since the positive materials have significantly lower graininess, higher resolution, and better sharpness than negative materials, one way to improve definition is to increase the size of the negative and make the prints by a reduction printing process. The question then arises as to what is the optimum size of negative relative to the positive, and at what stage of the process should the reduction take place.
"To investigate the first part of this question we prepared a series of negatives of a scene on Eastman Color Negative Film, Type 5248. The negatives had relative sizes of 1, 1.5, 2, and 3. The larger negatives were reduction printed on Eastman Color Positive, Type 5382, with a standard Acme printer. The reductions were such that all prints were of the same size as the contact print from the smallest negative. These prints were then judged for both definition and graininess. The print made at a reduction of 1.5:1 was judged by every observer to have better definition than the contact print. The prints made at reductions of 2:1 and 3:1 were not judged to be any better from the standpoint of definition than the print made at a reduction of 1.5:1. From the standpoint of definition, then, the optimum relative size of negative to positive is 1.5:1. When the same prints were judged for graininess, every observer chose the print made at a reduction of 2:1 over the print made at a reduction of 1.5:1. However, only 68 percent of the observers chose the print made at a reduction of 3:1 over the print made at a reduction of 2:1."
|I believe the above study can be taken as authoritative, and our own observations have already indicated that any increase in negative area much above 2 to 1 with respect to the standard 35mm area is wasteful and inconvenient unless special shapes of negative are required for other reasons than definition and grain reduction.|
|The comparison table below shows the relative negative area which is utilized by the various systems in making various types of prints:|
|SYSTEM WIDTH||NEGATIVE AREA||TYPE OF PRINT||NUMBER OF TIMES LARGER NEGATIVE AREA THAN 35mm|
|FOX||55 mm||55 mm Roadshow, 2.5:1||4|
|FOX||55 mm||35 mm CinemaScope, 2.5:1||4|
|MGM||65 mm||65mm Super Roadshow, 3:1||2.73|
|MGM||65 mm||65mm Roadshow, 2.5:1 ||2.24|
|MGM||65 mm||35mm CinemaScope 2.5:1||2.24|
|TODD AO ||65 mm||65mm Roadshow, 2.3:1||2.73|
|TODD AO||65 mm||35mm CinemaScope, 2.5:1||2.48 |
|VISTAVISION||35 mm, 8 hole||35mm 8-hole Roadshow, 2:1||1.64|
|VISTAVISION||35 mm, 8 hole||35mm Widescreen, regular release,1.85:1||1.78|
|VISTAVISION||35 mm, 8 hole||CinemaScope extraction||0.87|| |
| || |
|From the above you will note confirmation that the Fox negative is almost double the size that the Eastman Research group considers necessary, whereas the VistaVision negative falls below their requirements and in the event that Paramount were required to make a CinemaScope print from their negative they actually utilize less negative than if a straight 35mm camera were used.|
It will also be seen that MGM PANAVISION and Todd AO both have a safe margin of negative area above the optimum requirements in the Eastman paper.
- 9 -
If at any time for special purposes such as back-ground plates or for any other reason it were desired not to use our system with the mild anamorphosis in the taking lens, there would be no requirement for any change in equipment other than removing the anamorphotic element from the camera lenses, in which case a picture similar to the Todd AO picture at a ratio of 2.3 to 1 shape would be obtained with the high definition demonstrated by the use of the Panatar lenses.
- 10 -
The standard Mitchell pin-registering cameras we are using have a steadier and more reliable movement than the link-type cameras being used by Todd AO although ours are somewhat more noisy. The research already done on blimping our cameras indicates that the additional noise of our cameras can be successfully overcome.
- 11 -
MGM PANAVISION can be run on deep curved screens if it is so desired with no more detrimental effect than any of the other systems.
| || |
|Go: back - top - back issues - news index|