Daily Yellowstone journal., 1889-11-22
PHOTOGRAPHERS. eoLoRS.
II Can be Done, but Is not Generally
Understood, as II Has no Great Value.

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Capt. w. de w. Abney, in a paper
on the effect Of light on matter read
before the British association. said:
The question is often asked when pho
Biography in natural colors will be dis
covered. Photography in natural
colors not only has been discovered,
but pictures in natural colors have
been produced. am not alluding TO
the pictures produced by manual
work. and which have from time 10
time been foisted on a credulous pub
lie as being produced by the action of
light itself, much 10 the damage OF
photography aud usually to the so
called inventors. Roughly speaking,
the method of producing the spectrum
in its natural colors is TO chlorinize a
silver plate, expose it TO white light
till it assumes aviolet color, heat till
it becomes rather ruddy, and expose
1t TO a bright spectrum. The spectrum
colors are hen impressed in their nat
ural tints. Experiment has shown
that these colors are due TO an oxidiZed
product being formed at the red end OF
the spectrGn and a reduced product al
the violet end. Photography in natu.
raj colors. however, is only interest
ing from 4 scientific point Of view,
and, so far rs | can see, car never have
a commercial value.
A process - be useful must be one
by which reproductions are strictly
made; in other words. il must be n de
velcping and not a printing process,
and it n.st be taken in the camera,
for any printing process requires not
only a bright light, but also a pro
longed exposure. Now, il a be con-
ceiycd that in a substance which abb
serbs all Tie visible spectrum, the mol
ecules can be 80 shaken and sifted by
the different rays that eventually they
sort themselves into masses which re
fleet the particular rays by which they
are shaken: but it is almost-I might
say quitc-impossiblc 10 believe that
whcr this sitting has only been COM
mrn"ad, asit would be in the short ex-
posur To which a camera picture Is
submitted, the substance deposited to
builu up the image by purely chemi
cal means would be so obliging as to
deposit in that the particular size of par.
ticle which should give 10 the image
the color of the nucleus on which it
was depnsiting. am aware that in
the early days OF photography we
heard n good deal about curious re-
suits that had been obtained in mega
tives, where red brick houses were
shown as red and the blue sky as blu
ish. The cause Of these condolences
is not hard TO explain, and would be
exactly the same as when the red
brick houses were shown as blush and
the sky as red i'm a negative. The
records of the production Of the latter
negatives are naturally not abundant
since they would not attract much az
tention. may repeat then that pho
Biography in natural colOrs by "A print.
ing out process-by which / mean by
the action of light alonc-is not only
possible, but has been done; that
the production of a negative in natu-
raj cOlO!s might be produced appears,
in the present state Of our knowledge,
to be impossible. Surprising it were
not impracticable, il would be unsatis.
factory, us the light with which the
picture was impressed would he very
different from that in which it would
be viewed.
Artists are fully aware Of this diff
Guilty in painting. and take their pre-
cautions against it. The nearest aF
preach 10 success in producing pic.
lures by light alone is the method OF
taking three negatives OF the same
subject through different colored
glasses, complementary Ia the three
color sensations which together give
10 the eye the sensations Of white
light. The method is opened TO OBJ
lection on account Of the impure color
Of the glasses used. If a device could
be adopted whereby only those three
parts of the spectrum could be sever
ally used which form the color sensa-
tons, the method would be more per.
feet than il isat present. Even then
perfection could not be attained, ow-
ing 10 a defect which is inherent in
photography and which cannot be
eliminated. This defect is the imperfect
representation of graduation Of tone.
Forinstance, if we have a strip gradu.
ated from what we call black to white
iii must be rccoIlected that no tone
can scientifically be called black and
none white and photograph il, we
find hal in a print from the negative
the darkness which is supposed TO rep
resent a gray of equal mixtures OF
black and white by no means does SO
unless the black is not as black nor the
white as white as the original.