Journal of the Society of Motion Picture and Television Engineers (1950-1954)

in a camera for original photography, false color rendering of each area of the original scene would be obtained. Characteristics The emulsion and latent-image keeping properties of Eastman Color Internegative Film, Type 5245, and the storage requirements are similar to those previously described for Color Negative Film, Type 5248. Eastman Color Internegative Film is furnished on a clear safety base with jet antihalation backing in 400 or 1000-ft lengths. It is provided with American Standard Negative type perforations but having shorter pitch dimensions. * The speed of this material is very low and a high-intensity light source and efficient optical system are needed in the printer to obtain sufficient exposure. The contrast characteristics are appropriate for printing onto Eastman Color Print Film, Type 5382. They are somewhat higher than those of the former Color Internegative Film, Type 5243, hence lower contrast separation positives are required when printing onto this material than with the earlier type film. The graininess characteristics of this material are improved over the earlier type film. Processing Processing of Eastman Color Internegative Film, Type 5245, is carried out in the same solutions and in the same manner as used for processing Color Negative Film, Type 5248, with the exception that the color development time is 9 min. As with the Type 5248 Film, the actual processing times will vary somewhat with individual processing machines, depending upon the degree of agitation employed, replenishment rates, * Proposed American Standard, PH22.93, 35mm Motion Picture Short-Pitch Negative Film, Jour. SMPTE, 59: 527, Dec. 1952. etc. A typical processed color internegative is shown in Plate II. Process Control The procedures previously described for establishing a standard process for the Type 5248 Film apply equally well here. The sensitometer or scene tester used for exposing the sensitometric strips on Color Internegative Film should provide an intensity level and exposure time comparable to that which the film receives in a step printer. The sensitometric strips must be exposed in such a way as to give a neutral scale. This is required in order to permit calculation of the gammas for the separation positives. With such a neutral scale, approximate integral printing densities to red, green and blue light can be obtained using the filters shown in Fig. 3, in the densitometer. To make the neutral scale exposure on Color Internegative Film, it is necessary to make three separate, superimposed exposures with red, green and blue light, using the same filter combinations used when printing the separation positives onto the Color Internegative Film. The exposure times for the individual exposures which will result in a balanced exposure for the neutral scale must be determined by trial on the equipment being used. Suitable filter combinations for the three exposures are as follows: Exposure Kodak Wratten Filter Red No. 29 Green No. 16 plus No. 61 Blue No. 34 plus No. 38A When a sensitometer or scene tester is not available, it is possible to make these superimposed exposures in a printer. This requires a black-andwhite negative containing a step tablet on each successive frame, as nearly identical as possible. Such a negative could be made in a title camera by photographing a precalibrated gray Hanson and Kisner: Improved Color Films 695