Oz color difference

[old_tv_nut]

I have a copy of "Colour Cinematography" (1951) by Adrian Cornwell-Clyne, which has an extensive section on Technicolor. It has a diagram of the printing machine. It gives some formulas for dyes, with a warning that they are presented for schematic purposes only and different ones may have been used. It gives no spectral curves.

The closest thing I have is a neutral density spectral curve that was published as part of a BBC paper in the mid 60s about the problems of low deep-red and infrared density of Technicolor dyes causing a red fog when televising these movies. This ND curve is convincing, as it shows the decreasing density towards deep red, which was also a known problem for Technicolor dye sound tracks that caused the use of a silver soundtrack instead. Unfortunately, there is no determinate way to separate the neutral density spectrum into the three individual spectra for Y, C, and M.

Edit: Regarding the variability when printing to chromogenic film, references say the Technicolor dyes were changed significantly in 1946, producing denser and more neutral blacks, and eliminating the need for a silver base image. Technicolor dyes (the later ones, I presume) were also said to produce better color than Kodachrome (which version, they don't say).