Process 4: Development and introduction

Ending card for a 1936 Warner Bros. Merrie Melodies cartoon with an "In Technicolor" credit. Many animation companies during the 1930s and 1940s used Technicolor for their cartoon shorts.

Technicolor envisioned a full-color process as early as 1924, and was actively developing such a process by 1929. Hollywood made so much use of Technicolor in 1929 and 1930 that many believed the feature film industry would soon be turning out color films exclusively. By 1931, however, the Great Depression took its toll on the movie industry, which began to cut back on expenses. The production of color films had decreased dramatically by 1932, when Burton Wescott and Joseph A. Ball completed work on a new three-color movie camera. Technicolor could now promise studios a full range of colors, as opposed to the limited red-green spectrum of previous films. The new camera simultaneously exposed three strips of black-and-white film, each of which recorded a different color of the spectrum. The new process would last until the last Technicolor feature film was produced in 1955.

Technicolor's advantage over most early natural-color processes was that it was a subtractive synthesis rather than an additive one: unlike the additive Kinemacolor and Chronochrome processes, Technicolor prints did not require any special projection equipment. Unlike the additive Dufaycolor process, the projected image was not dimmed by a light-absorbing and obtrusive mosaic color filter layer. Very importantly, compared to competing subtractive systems, Technicolor offered the best balance between high image quality and speed of printing.

The Technicolor Process 4 camera, manufactured to Technicolor's detailed specifications by Mitchell Camera Corporation, contained color filters, a beam splitter consisting of a partially reflecting surface inside a split-cube prism, and three separate rolls of black-and-white film (hence the "three-strip" designation). The beam splitter allowed ⅓ of the light coming through the camera lens to pass through the reflector and a green filter and form an image on one of the strips, which therefore recorded only the green-dominated third of the spectrum. The other ⅔ was reflected sideways by the mirror and passed through a magenta filter, which absorbed green light and allowed only the red and blue thirds of the spectrum to pass. Behind this filter were the other two strips of film, their emulsions pressed into contact face to face. The front film was a red-blind orthochromatic type that recorded only the blue light. On the surface of its emulsion was a red-orange coating that prevented blue light from continuing on to the red-sensitive panchromatic emulsion of the film behind it, which therefore recorded only the red-dominated third of the spectrum. 

Each of the three resulting negatives was printed onto a special matrix film. After processing, each matrix was a nearly invisible representation of the series of film frames as gelatin reliefs, thickest (and most absorbent) where each image was darkest and thinnest where it was lightest. Each matrix was soaked in a dye complementary to the color of light recorded by the negative printed on it: cyan for red, magenta for green, and yellow for blue (see also: CMYK color model for a technical discussion of color printing). 

A single clear strip of black-and-white film with the soundtrack and frame lines printed in advance was first treated with a mordant solution and then brought into contact with each of the three dye-loaded matrix films in turn, building up the complete color image. Each dye was absorbed, or imbibed, by the gelatin coating on the receiving strip rather than simply deposited onto its surface, hence the term "dye imbibition". Strictly speaking, this is a mechanical printing process, very loosely comparable to offset printing or lithography, and not a photographic one, as the actual printing does not involve a chemical change caused by exposure to light. 

During the early years of the process, the receiver film was preprinted with a 50% black-and-white image derived from the green strip, the so-called Key, or K, record. This procedure was used largely to cover up fine edges in the picture where colors would mix unrealistically (also known as fringing). This additional black increased the contrast of the final print and concealed any fringing. However, overall colorfulness was compromised as a result. In 1944, Technicolor had improved the process to make up for these shortcomings and the K record was eliminated.

Early adoption by Disney

Kalmus convinced Walt Disney to shoot one of his Silly Symphony cartoons, Flowers and Trees (1932), in Process 4, the new "three-strip" process. Seeing the potential in full-color Technicolor, Disney negotiated an exclusive contract for the use of the process that extended to September 1935. Other animation producers, such as the Fleischer Studios and the Ub Iwerks studio, were shut out – they had to settle for either the two-color Technicolor systems or use a competing process such as Cinecolor. 

Flowers and Trees was a success with audiences and critics alike, and won the first Academy Award for Best Animated Short Film. All subsequent Silly Symphonies from 1933 on were shot with the three-strip process. One Silly Symphony, Three Little Pigs (1933), engendered such a positive audience response that it overshadowed the feature films with which it was shown. Hollywood was buzzing about color film again. According to Fortune magazine, "Merian C. Cooper, producer for RKO Radio Pictures and director of King Kong (1933), saw one of the Silly Symphonies and said he never wanted to make a black-and-white picture again." 

Although Disney's first 60 or so Technicolor cartoons used the three-strip camera, an improved "successive exposure" process was adopted circa 1937. This variation of the three-strip process was designed primarily for cartoon work: the camera would contain one strip of black-and-white negative film, and each animation cel would be photographed three times, on three sequential frames, behind alternating red, green, and blue filters (the so-called "Technicolor Color Wheel", then an option of the Acme, Producers Service and Photo-Sonics animation cameras). Three separate dye transfer printing matrices would be created from the red, green, and blue records in their respective complementary colors, cyan, magenta and yellow. 

Successive exposure was also employed in Disney's "True Life Adventure" live-action series, wherein the 16mm Kodachrome Commercial principal photography element was first duplicated onto a 35mm fine-grain SE negative element in one pass of the 16mm element, thereby reducing wear on the relatively small 16mm element and also eliminating registration errors between colors. The live-action SE negative thereafter entered other Technicolor processes and were incorporated with SE animation and three-strip studio live-action, as required, thereby producing the combined result. 

Convincing Hollywood

The studios were willing to adopt three-color Technicolor for live-action feature production, if it could be proved viable. Shooting three-strip Technicolor required very bright lighting, as the film had an extremely slow speed of ASA 5. That, and the bulk of the cameras and a lack of experience with three-color cinematography made for skepticism in the studio boardrooms. 

An October 1934 article in Fortune magazine stressed that Technicolor, as a corporation, was rather remarkable in that it kept its investors quite happy despite the fact that it had only been in profit twice in all of the years of its existence, during the early boom at the turn of the decade. A well-managed company, half of whose stock was controlled by a clique loyal to Kalmus, Technicolor never had to cede any control to its bankers or unfriendly stockholders. In the mid-'30s, all the major studios except MGM were in the financial doldrums, and a color process that truly reproduced the visual spectrum was seen as a possible shot-in-the-arm for the ailing industry. 

In November 1933, Technicolor's Herbert Kalmus and RKO announced plans to produce three-strip Technicolor films in 1934, beginning with Ann Harding starring in a projected film The World Outside.

Live-action use of three-strip Technicolor was first seen in a musical number of the Metro-Goldwyn-Mayer feature The Cat and the Fiddle, released February 16, 1934. On July 1, MGM released Hollywood Party with a Technicolor cartoon sequence "Hot Choc-late Soldiers" produced by Walt Disney. On July 28 of that year, Warner Bros. released Service with a Smile, followed by Good Morning, Eve! on September 22, both being comedy short films starring Leon Errol and filmed in three-strip Technicolor. Pioneer Pictures, a movie company formed by Technicolor investors, produced the film usually credited as the first live-action short film shot in the three-strip process, La Cucaracha released August 31, 1934. La Cucaracha is a two-reel musical comedy that cost $65,000, approximately four times what an equivalent black-and-white two-reeler would cost. Released by RKO, the short was a success in introducing the new Technicolor as a viable medium for live-action films.

La Cucaracha On XOTV

The three-strip process also was used in some short sequences filmed for several movies made during 1934, including the final sequences of The House of Rothschild (Twentieth Century Pictures/United Artists) with George Arliss and Kid Millions (Samuel Goldwyn Studios) with Eddie Cantor.

Pioneer/RKO's Becky Sharp (1935) became the first feature film photographed entirely in three-strip Technicolor. Initially, three-strip Technicolor was only used indoors. In 1936, The Trail of the Lonesome Pine became the first color production to have outdoor sequences, with impressive results. The spectacular success of Snow White and the Seven Dwarfs (1937), which was released in December 1937 and became the top-grossing film of 1938, attracted the attention of the studios.

Limitations and difficulties

One major drawback of Technicolor's three-strip process was that the cameras required a special, bulky, large volume sound blimp. Film studios could not purchase Technicolor cameras, only rent them for their productions, complete with camera technicians and a "color supervisor" to ensure sets, costumes, and makeup didn't push beyond the limitations of the system. Often on many early productions, the supervisor was Natalie Kalmus, ex-wife of Herbert Kalmus and part owner of the company. Directors had great difficulty with her; Vincente Minnelli said, "I couldn't do anything right in Mrs. Kalmus's eyes." Kalmus preferred the title "Technicolor Director", although British licensees generally insisted on "Colour Control" so as not to "dilute" the film director's title. She worked with quite a number of "associates", many of whom went uncredited, and after her retirement, these associates were transferred to the licensees, with, for example, Leonard Doss going to Fox where he performed the same function for Fox's DeLuxe Color. 

The process of splitting the image reduced the amount of light reaching the film stock. Since the film speed of the stocks used was fairly slow, early Technicolor productions required a greater amount of lighting than a black-and-white production. It is reported that temperatures on the film set of The Wizard of Oz from the hot studio lights frequently exceeded 100 °F (38 °C), and some of the more heavily costumed characters required a large water intake. Some actors and actresses claimed to have suffered permanent eye damage from the high levels of illumination.

Because of the added lighting, triple amount of film, and the expense of producing dye transfer projection prints, Technicolor demanded high film budgets.