Los Angeles herald., 1910-08-14
Ga ART AND PAsTIME
OF PHOTOGRAPHY

since the ADVENT OF photography IT.
self nothing has so stirred the enthu-
siasm of the devotees of this method OF
picture making as the invention an6
perfection of a process for securing
photographs in natural colors by the
Messrs. Lumiere Bros. of Lyons, France
Their tireless and even painful efforts
have been crowned with success and to-
day so simplified is their process that
any careful worker may secure results
that will render him or her more or less
delerious. Their method produces pic
lures on glass only, no prints being
possible on paper, but as transparencies
are perhaps the most beautiful of all
photographs even when uncolored, this
is not at all disappointing, creating a
higher value for each result from the
fact that indiscriminate duplication is
not likely.
The Lumiere "Autochrone" plates
are prepared by first coating the glass
plates with myriads of infinitesimal
starch grains dyed orange, green and
violet, and distributed in somewhat
promiscuous profusion. Upon the top OF
this coating is then placed a delicate
panchromatc emulsion; the plate is
then ready for the camera, and any
plate camera can be used, a specially
prepared ray screen is placed in front
of the lens and exposures made
through same. The plate is placed in
holder with its emulsion side away
from the lens, just reversing the usual
method. This is necessary in order to
pass all the light through the screen
of starch grains on the plate and to
counteract the reversal the ground
glass of camera should be turned to
have its ground side facing the back
of camera; this avoids the necessity
for making allowance for thickness of
the plate when focusing and corrects
the registration.
Exposures in good sunlight can be
made in about one or two seconds
with diaphragm at F'S to FIJI for open
landscapes while portraits out of doors
would require about twice as much.
Indoor exposures of grouping of fruit,
flowers or chinaware and similar OBJ
jects can be exposed without danger of
movement and from 20 seconds up
wards can be managed. After the ex-
posure comes the developing. This
should be done in practically total
darkness by timing, and 21a minutes in
the developer is all that is necessary.
An excellent dodge is to have an ac-
complice who is also keen on this work
and arrange so that one person is out
side the darkroom while the other is in
side, so that the starting and stopping
signals can be safely arranged for.
After the development time is over
the plate must be quickly rinsed in
plain water and then immersed in a
solution of potassium permanganate
and sulphuric acid in water made up
just before beginning development and
then carried out into bright daylight.
The plate will then gradually c!ear and
the colors become visible when plate
is viewed by transmitted light. This
clearing both requires about minutes
after which another rinse for 80 to 40
seconds. To avoid possibility of frill-
ing in warm weather a hardening bath
of chrom alum can be used at a
strength of a l per cent solution for 2
minutes. When rinsed from this the
plate is transferred to the same de-
veloper as was first used and redevel-
oped until the light parts of picture
have turned completely black.
After this comes the final washing
in running water for 3 or 4 minutes.
then the plate should be put to dry
in a fairly cool place where there is
plenty of air circulating, though not
roughly as would be the case where
a fan was in use. Drying should not
take very many minutes, and can be
followed by vanishing to protect the
surface before binding wI.n coeVr
glass.
The exposure should be exact for
successful results by this method but
there is a modified development which
allows some little opportunity of con-
troll in case of error in exposing. The
use of an exposure meter is almost es-
sential to success in this and the speed
given by Wynne is FS for outdoor use.
A number of autochrome pictures
have been submitted to me lately for
examination and some most beautiful
pictures were among them. Two or
three seascapes and some figure stud