Re: Kodachrome.

[Paul Schliesser <paulsc@eos.net>]

>The difference between Technicolor and later color systems is that with
>Technicolor the dyes are introduced in the film when development is finished
>while in the other processes color is formed during (color)development via a
>reaction between development fall-out products and coupling agents present
>in each of the layers of the film.

Kodachrome and the 1930s Technicolor don't have anything in common. 
Technicolor original negs consist of three separate BW negatives on 
separate reels, one reel each for red, green and blue. It's only when the 
positive prints are made that any color dyes are introduced, so you 
should be able to pull pristine prints from them for as long as the BW 
negs last. The positive Technicolor prints fade and show color shifts as 
they age, just like any other color film.

Warner went back and made new prints of a bunch of Technicolor movies 
(including Robin Hood) in the 1970s, when they had their 50th 
anniversary. I remember being blown away by the color, having only seen 
old, faded prints before that. I wondered how the original audiences, 
accustomed to BW, reacted to the film when it was first released.

Technicolor necessitated a lot of mechanical and optical complexity to 
shoot and print it. There were also a lot of problems for the 
cinematographer. The camera contained prisms and filters to split the 
light coming into the camera into three separate images and filter each 
one. Even if everything is optically perfect (and this was before lens 
coatings), only 1/9 of the light that came through the lens got to the 
film. You needed to drench the sets and actors with light in order to get 
a useable image on the slow films of the time. Even though later 
processes were less stable and of lesser quality, they were much cheaper 
and easier to use.

Even very stable color films like Kodachrome WILL fade, especially if 
they spend a lot of time in projectors or on light tables. If you are 
really worried about the long-term health of your chromes, get a 
chest-type freezer and freeze them.

- - Paul