The daily morning journal and courier. [volume] (New Haven, Conn.) 1894-1907, 1900-12-15
PHOTOGRAPHY IN CoLoRs.

! Professor Metz or Iulane university
Medical college gave demonstration Of
the recent results of color photography
in the ampithetre of the medical depart
ment before number of invited guests
His demonstration consisted of a num-
Der of photographs projected upon a
screen by means of a modification OF
the stereopticon. Each picture present
ed the subject in its natural colors
Every color and tint was perfect. from
the palest neutrals to the most vivid
reds blues, green's and yellows. Bou-
quets of flowers of the most delicate
beauty the vivid patterns of Turkish
and Persian rugs. the loveliest land
Escapes and lifelike portraits follow each
other in rapid succession, and as the
very acme of the art as now developed,
1.-TWO sunset views We're presented, where
the lustre of the sunshine breaking
Through roseate and golden clouds was
seen in all the splendor Of nature her.
self. Even the metallic sheen of the
butterhy's wing and the iridescence of
Bohemian glass were caught and fast
ened by the magis art.
Color photography, he said, brought
into play the principles of physiology,
as well as those of physics, explaining
that by the physiological element in
volved he meant the production upon
the eye of the impressions necessary to
convey to the brain the conception of
colors in their natural sequence, while
by the physics involved he meant the
composition of the plates and the per-
fecting of the process so that the rays
of light should produce a true record
of the colors intended to be produced
in the projection of the picture from the
negative He explained that q color
photograph Is not q photograph in col
ors, but is merely a record of the color
| impressions, Just as the film of the
kaleidoscope is a record of motion and
the cylinder of the photograph is a rec
ord of sound.
| There are three methods Of color pho
Biography, he explained, all Of which are
defective. One, the Ives process, more
nearly approximates perfection than the
others. This process he thought the
most practical and freest from obiec-
ton. The second process, he said,
could scarcely be said to have a prac-
t1cal existence. The other process, that
of Lippman depends upon the inter-
ference Of light waves. 1t gives very
satisfactory results, but is open to sew
eral very serious objections on account
of it's lack of luminosity and of the me-
chanical arrangement, screen of fine
lines giving the picture produced me-
ehanical appearance. In the specimens
shown 1t seemed that the latter process
was best adapted to the showing of
very vivid and well defined colors, while
the first, or Ives, process was best adj
apted to the production of delicate eff
fects.
The process favored by Professor
Metz is the Ives. The principle of this
process, as he explained it, is the break
ing up and recombining of light There
are three primary colors-red green and
blue-and from these in combination
all other colors or shades of colors from
violet to red are produced, and from
combination of the three together white
Iieht results. He illustrated the COM
position of culors with a mechanical
device by which a disk, divided into
sections, each showing different col
or. was rapidly revolved, producing an
impression of the resultant color ana
from the combination. This was much
more beautifully illustrated by slide
of three primary colors. Separated
the three images on the screen We're
vivid blue green and red. They were
brought slowly together, and as the
edges of the color fields overlapped the
result Of the combination was apparent
until tba thVnp color |
fields coineided, and the effect was
seen in a vivid white. 1t is unon TINS
of color in white light |
that color photography depends. And
this color is merely matter of motion.
The wave undulations of red light are
but four hundred and eighty-six billions |
per second. and there is q correspond
ing increase of the chemical action of |
light from red to blue. 1t is upon this !
that the photographer depends. In the |
camera used to take the negatives in
tended to produce the colored picture |
the lenses are so arranged that the light |
from the object is sifted, as it were, |
the blue rays being projected to one |
part of the plate, the green rays to an
other and the red rays to third, thus
three images upon the plate,
each with a different Intensity of chem
ical action.
The plate is the same for all images
and as consequence the red light pro-
duces less action, the green more and
the blue still more upon the film of sill
YER upon the plate. 1t can be seen,
then, that upon projecting correspond
ing colors of light rays through the
negative thus formed a reversal of the
sitting process takes place, and when
he three Images are combined and
east upon the screen together, the re-
suit is to allow the passage of those
'ays that correspond to the colors in
he object photographed in the exact
that those rays had in the
original, and the picture produced is in
is natural colors. To illustrate this
Professor Metz showed the three imag-
IS of each picture in primary co1ors
IND combined them on the screen by
imply bringing the images together
The result looked like magic and most
lssuledly would have condemned the
professor to the stake in less enlight-
ned age.
In the second process illustrated the