RESTORATION PROCESS FROM TECHNICOLOR ELEMENTS
Contents
Notes to introduce the schematic diagrams of Technicolor restoration routes.
The diagrams were made to illustrate the various routes known to be used by laboratories and archives, and to illustrate the contrast rule:
The contrast of the overall reproduction of a photograph is a product of the individual contrasts of the films stocks used. The preferred overall contrast of a projected image is approximately 1.5.
Technicolor imbibition processes
A Technicolor print is one made by the Technicolor Corporation. The Technicolor processes began in 1917 and the last Technicolor imbibition print was made in Europe in 1975, although there is a current project in Los Angeles to produce a modern imbibition print system, planned to start production in 1998. The Technicolor Corporation gave its name to many different colour printing methods as the companies researchers searched for a commercial method of making colour prints for cinema release.
The method that is largely synonymous with the name Technicolor is a dye transfer printing process, virtually a graphic arts printing system, that began in 1935 and continued to the 1970’s, sometimes called "imbibition printing". There were other dye transfer processes for both still and cine film.
The Technicolor process used initially a patented three-strip camera to produce three separation negatives. Sequential frame or single strip separation negatives were used from animation graphics for the same printing method. Cementing film elements together and other ideas were tried initially. In 1935 the 3-colour imbition system was introduced, together with a patented 3-strip camera using a prism, a bipack [previously used for 2-colour by many companies] and a single green record film. The red separation negative image was reversed in geometry from the other two and was corrected at the first printing stage to the matrix.
[The reversed geometry of the red image is not a reliable method of identifying Technicolor separations. Other less common 2- and 3-colour systems produced reversed separations.]
Diagram of Technicolor 3-strip system route of about 1935
In the 1940’s the "monopack", a 35mm Kodachrome film, also occasionally later 16mm, was used as the camera film as a lightweight alternative to the three-strip camera. In the 1950’s colour negative film replaced three-strip and monopack as the camera material. In all instances where a colour film was used in place of the separation negatives a set of separations was made to create the matrices.
Also in the 1950’s Kodak produced a pan separation matrix film that allowed the positive matrices to be made directly from a colour negative just as they had been from the camera separation positives.
The Technicolor processes all required considerable handling of the many elements with the risk of damage at many points in the sequence, and positive "protection masters" were [always] made before printing and after negative cutting to allow new separation negatives to be made in the case of damage. These were black and white film prints of the separation negatives, usually on a film stock of gamma 1.66, specially made as an insurance against damage of the sep negs. Pro-masters are therefore positive and the red separation is the same geometry as the other two colours [i.e. is reversed in printing]
The contrast and method of making protection masters did change over the years as the different camera originals changed. The camera original materials were negative film, colour or black and white with a development gamma of 0.60 or were various reversal originals like Kodachrome with a contrast in excess of 1.0, and generally the positive protection masters were made to have overall reproduction contrasts of 1.0.
Technicolor dyes changed as the years went by just as the technology of printing changed and some periods saw complex mixtures of dyes used as the primaries. These became single dyes in later years.
Technicolor is often felt to have a single visual print character that is recognizable, but in reality, there were many different appearances, with relatively the high contrast and saturation and a restricted but bright colour range in common.
Restored prints from Technicolor separation negatives and positives
Laboratories that make colour restoration or access prints from separation negatives suffer from several uncertainties.
1 Different clients prefer different visual appearances in the finished print. Sometimes the differences are slight but sometimes a client will reject a print that is similar in appearance to an original Technicolor imbibition print, preferring a lower contrast result more like a modern Eastman Colour print film from a modern negative. Soho Images has clients that state that they do not want an image that looks like the original Technicolor print.
2 Technicolor prints do not fit the requirements of Television well and inexperienced television engineers often reject both original and restored Technicolor images as outside the specified quality guidelines. {German TV companies are well known for this inflexibility]
The optical effects, fades and dissolves for example, were for a long period, made as duplications of the entire scene, or pair of scenes, and these are clearly seen as being one or more generations more than the rest of the picture. Sometimes clients reject restorations [or even originals] asking that these opticals be improved to match the rest of the film!
3 Some clients define the route by which the restored print must be made and this may not enable the laboratory to provide the optimum result.
4 Many restored prints must be made from existing elements provided by the client, and which were made since the original separations were produced. Colour Reversal Intermediates, Duplicate negatives on Eastman [or Fuji] Colour Intermediate films of various vintages all produce different print results outside the control of the laboratory, but which are criticised as not being the "required" quality.
[We have made prints from old Colour Reversal Intermediates made by Technicolor, e.g. "The Ladykillers", which produce prints that look nothing like Technicolor; more like desaturated Eastman.]
5 Technicolor produced it’s own protection master positives from original camera separations as a means of recreating a new separation negative in the event of damage or loss. The aim contrast varied at some periods but generally was intended to have an overall reproduction contrast of 1.00. However protection masters are not consistent, and prints made from them rarely if ever equal the print quality of prints from original camera separations, but this is not appreciated by clients in general. Some archives have extensive collections of these protection masters, which may never have been used to produce a print.
[In the case old "Ideal Husband" the NFTVA asked Technicolor to make a restored print in the early 1980’s but could only locate pro-masters in some colours. The results were unacceptable to the archive and they asked Paul de Burgh to try instead. Paul had to wait until the full set of original negatives was finally discovered before he could make a reasonable print.]
6 Separations were [perhaps occasionally are] made as protection masters from other colour original films especially from integral colour negatives [e.g. on Pan Separation Film]. The procedure, contrasts and the film stocks used were [are] different from the procedure for producing Technicolor protection masters, and the resulting restored prints are visually different, but clients rarely recognize this.
7 Sometimes one separation element is lost. In some cases it is possible to "reconstruct" an alternative from the remaining separations. The results will never be correct.
8 As with most colour archive film restoration it is necessary to use whatever film stocks are available, in a non-standard manner, to obtain a restored print. The contrast rule is invaluable as a simple guide to planning the route, but is little understood in archives. Ensuring that the film layers track well when non-standard processing or when flashing is used is essential and routine sensitometry is essential. The LAD method is adequate for most standard duplication methods but the "full curve" or "two point" system of Kinsey and Gale is necessary if the method is not routine.
[Eastman Colour Internegative contrast reduction is best carried out by selective layer flashing and "pull processing" to achieve a consistent result.]
Most laboratory technologists recognize these problems and have felt that the answer may lie in education of the client to recognize that restoration is a procedure of using modern film stocks [designed for modern production routes] in non-standard ways to imitate the original procedures.
The technical literature contains a number of recommendations for restoration routes and these are sometimes in conflict with one another. Presumably the variation is linked to the variation in preferences for the final print result.
The enclosed diagrammatic routes show just some of the published recommendations. In these diagrams the contrasts of the stocks and, where relevant, the printing method are shown. These values demonstrate that the contrast rule can be applied and that the usual preferred final overall reproduction contrast of 1.5 can be achieved in every case. Optical printing of Black and White film increases the contrast of the result by up to 20%. This effect does not occur with contact printing and colour film is increased in contrast too little to take into account.