ZorkiKat
Member
You mention the AGFA approach. I realize that they made an early AGFAcolor film, but I have no idea how it worked.
Could you explain in a little more detail?
The additive 1932 Agfacolor plate used coagulated dyes instead of starch in the mosaic filter grid. Worked in the same principle as the Lumieres' Autochrome in terms of separating, recording, and reproduction of the hues.
The description described in Brian Coe's "History of Colour Photography" says that the filter grid starts out as a
"mixture of three solutions of dyes in colloidal suspension. The elements in suspension were immisible but would coagulate, so that when they were coated on glass or film and allowed to dry, the dyed droplets formed into individual red, blue, and green filters. Furthermore, because the elements dried in close contact with each other, there were no interstices to be filled in with carbon black as was necessary for the Autochrome. In fact, it claimed that whereas some 92% of incident light was absorbed by the filter layer of an Autochrome plate, only 86% was absorbed by the Agfacolor mosaic."
The less light lost from absorption made Agfacolor faster than Autochrome. The film version of additive Agfacolor was Agfacolor Ultra.
Agfacolor-Neu was the tri-layered subtractive version which had colour couplers in the emulsion layers.
AgX must be proposing that since the Agfacolor used different materials which no longer required the flattening and carbon filling steps in Autochrome,
the former may be more feasible to work with.
Another method would be forming the filter mosaic with red, blue, and green lines, like what Dufaycolor did.
Brian Coe's book also shows a comparison (at 50X magnification) of the various filter mosaics used by the different systems. Dufaycolor's (the grid made it more consistent in terms of filter distribution) and Agfacolor Ultra's mosaics were the finest in the lot.
Jay