[LargeFormat] WWII signal Corp newsgroups

[Richard Knoppow]

----- Original Message -----
From: "philip.lambert" <philip.lambert@ntlworld.com>
To: <largeformat@f32.net>
Sent: Friday, January 03, 2003 12:23 AM
Subject: Re: [LargeFormat] WWII signal Corp newsgroups


> When was colour film first available?  I vaguely heard
about Dufaycolor, a
> reseau of coloured starch granules was it? Early 20th
century perhaps.PL
>
>
  I am not sure of the dates without doing some research.
Dufay Color seems to me to have originated in the 1920's.
Dufaycolor was one of the later "screen plates". These are
additive positive color films using a reseau of color filers
over the emulsion. The filter may take the form of strips of
pigments coated over the surface of the support or of
colored grains of starch or other material under the
emulsion. The emulsions are essentially conventional single
panchromatic emulsions processed by reversal. Screen plate
processes date from before 1900.
  There were other methods of single film color manufactured
commercially at one time or another. For instance, Kodak
made a lenticular motion picture film under the name
Kodacolor in the late 1920s. Lenticular color film again has
a conventional single panchromatic emulsion. The three color
images are produced by a series of semicylindrical lenses of
very small size molded into the back side of the support.
These are called lenticules. The lens has a striped filter
on it. The lens must be fast, not only to compensate for the
rather slow film but to give a large enough difference in
angle to the color stripes coming from it. These stripes are
imaged on the film by the lenticules. Some attempt at
application to theatrical motion pictures was made by
Paramount Pictures in co-operation with Kodak, in the early
1930's but the problem of reproduction of the lenticular
film proved insurmountable. The system also has problems
with color fringing around out-of-focus elements in the
image.
  There are two classic histories of color photography. Both
were reprinted by Focal Press and are somewhat available
although the originals are very rare.
1, _The History of Three Color Photography_ E.J.Wall, First
Edition, 1925, the Focal Press, London, reprint, 1970,
London, The Focal Press, ISBN 0-240-50702- 9
  It should be noted that for some reason Wall decided to
minimise the value of the extensive work done by F.E.Ives,
apparently due to a personal animosity.

2, _History of Color Photography_ Joseph S. Friedman, Phd,
original edition 1944, reprinted 1956, (Boston) The American
Photographic Book Publishing Company. Reprinted 1968,
(London) The Focal Press Limited ISBN 0-240-44888 X.

  One should also consult _From Dry Plates to Ektachrome_
C.E.K.Mees, The Eastman Kodak Company. my copy is hiding
under something right now so I don't have further
publication data.

  There are some articles by Herbert T. Kalmus, one of the
founders of Technicolor, on the web. A Google search for his
name will find them.
  Technicolor used a method of producing color separation
negatives in the camera and printing with dye transfer.
Their first attempts were a two color process using
bi-packed or duplitized film. In 1935 Technicolor released
their three-color system using a special color separation
camer which shot three strips of film at the same time. This
camera was used until 1951 when it was replaced by standard
cameras using Eastman Color Negative film. The dye transfer
printing process was continued until the mid 1970's.
Technicolor is trying to reintroduce the printing process
now.

  The two books mentioned above should be available through
larger library systems. They will give you about as good an
overview of early color processes as can be had along with
some of the roots of modern processes.
  I should add that attempts at natural color photograhy go
back to the earliest photographs. It is quite common to find
hand colored Daguerreotypes and hand coloring was applied to
all other forms of photographic images, including the
individual coloring of motion picture frames.


---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com