By placing in front of the lens a color-screen
consisting of a small glass tank containing a weak solution of bichromate
of potash, to cut off part of the blue and violet light, I obtained, with
these chlorophyl plates, the first photographs in which all colors were
reproduced in the true proportions of their brightness. But my chief
desire at that time was to realize a method of producing from any object
in colors a set of three negatives, in one of which the shadows should
represent the blue of the original, in another the yellow, and in another
the red, in such a manner that transparent pigment prints from these
negatives--blue, yellow, and red--would, when superimposed on a white
surface, represent not only the lights and shadows, but also the colors
of the object. This had already been attempted by others, who failed
because their plates were not sufficiently sensitive to red and yellow.
Having succeeded perfectly in my undertakings, I published my discovery
in 1879,[1] explaining how to prepare and use the chlorophyl plates, in
connection with the yellow screen, for the purpose of securing correct
photographs of colored objects.[2]
[Footnote 1: _Philadelphia Photographer_, December, 1879, p.
Pages:
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78