T3D Glorious Technicolor

[Bob_Maxey@xxxxxxxxxxxx]

Understand that there were several different versions of Technicolor. So to
discuss how the process works, you have to be specific about the specific
process used. For example, the current process is called Technicolor
Process #6. This uses modern chemistry and better film stocks. It is a
3-Color dye imbibtion process.

Technicolor Process #2 was a three strip process, but 2 of the strips were
exposed in a bi-packed arrangement. A cube beam splitter directed the
incoming light and exposed one of the bi-pack strips coated with the red
coated emulsion to receive the blue information. The other part of the
bi-pack  received the red information and the third strip was not
bi-packed. It received the green information.

This configuration used red-coating applied to the emulsion side of the
blue info recording film stock.  This allowed for two of the three films to
be run bi-packed.   Light passed through the film-base of the first
bi-packed film to expose the blue-sensitive black & white emulsion.  This
emulsion was blind to the red portion of the spectrum.  The red portion of
the scene then continued through the red coating and hit the other
bi-packed panchromatic film strip.  The blue portion was effectively held
back by the filtering action of the red coating.  This arrangement provided
a separation with which to carry out the dye-transfer color process.
Applying a red filter coating to the emulsion of the blue sensitive film
stock meant that only one of the three films needed to be different.

The green image left the prism directly.  The red and blue images left the
prism reversed by the silvered mirror.  The blue recording film was flopped
in the camera so that the light went through the film-base.  This
reoriented the image-to-emulsion position so that it matched the
orientation of the green image.  This left the red image laterally
reversed. All three negative images were finally brought into alignment
during the rest of the process which included making matrices and final dye
transfer printing.

The required filters were used at the cube splitter and were probably not
Dichroic. The cube splitter had a partially silvered center. I would bet
the filters were not dichroic, and if someone knows for sure, I would like
to know.

Cheers,

RM