The sun. [volume] (New York [N.Y.]) 1833-1916, 1900-07-15
PHOTOGRAPHY IN C0L0RS.
4 PROCESS WHICH SCIENCE HAS
YET 70 MAKE PRACTICABLE.
Only Methods Vet approaching Success Too
Costly and Iabsrlous to Rc % Much Use
A Seeing Machine which Produces the
Eject Of Perfect Color PhOtos rsphy.

Eject of Perfect Color PhOtos raphy.
About once in two ar three wears some one
processes 10 have solved The problem of color
photography; but the Photographic world
doesn't become wildly excited over these Gsser-
tons, a. it did formerly. Too many Of the p.c--
e>ses have proved To be fake, pure and simple,
and those founded upon scientific truth have
| been only notifications Of earlier discoveries.
Color photography has been IA fascinating
problem Tor scientists ever since tho early
part Of this century, In Isle Prof Scebeck Of
Jena made some interesting experiments in the
reproduction of the natural colors Of the spec
rum, and u host Of scientists followed his lead.
Becauerel IN laS succeeded in reproducing all
of the hues of The ~rcctrrm upon a plate covered
with a film of violet ,ubchloride of silver, and
even photographed various objects in their
natural colors, but found no way OF fixing these
tints 80 that they would stand exposure 10 tho
light. Other men experimental and obtained
VARYING results by modified chemical processes,
but the instability of color baf'ed them, as it had
bafled Becqncrel 1t wn- one thing to under.
stand that mnriatc of silver, through reflection
/ and interference OF light rays among It's parA
iicles, would take the colors Of the spectrum,
and quite another thing TO fix these colora
permanently when they had been obtained.
MANY scientists have abandoned the idea that
n direct Photography in color, with resulting
permanent and satisfactory prints. will ever
be obtained, Othsre, more optimistic. insist
that the thing l. n possibility, even though o
remote one. In the meantime what Develop
meni does occur lies along one of two lines,
either being based upon the trichromatic theory
of vision. and composite photography, or fol-
lowing lippman's interierentisl method, found.
ed upon the law Of wave vibration in light.
Iippnan'> discoveries in color Photography
were really tho last 10 stir w any great excitAs
mont among scientists. NJ. Iippman was n PROF.
lessor of physics In the Sorbonne, with no
practical knowledge Of photography. Not even
the kodak mania had marked him for its own:
hat he knew n thing or two about abstract
physics and in the course Of lectures TO young
France on the subject of acoustics and the
neutrnli7ing Of sound by the meeting Of adj
NanCin. and reflected sound waves. II occurred
To him that tho same theories applied TO color
would produce color photographs. He turned
to photography and demonstrated his theory
To his own satisfaction and the edifcation Of tho
scientific world, bat he never attempted to
max" commercial proht ut his discovery and
went on ,eren"Iy Occurring upon abstract ply
sIrs. The results he obtained are what might
be- expected of 50 theoretical n scientist. He
Internationally accomplished the nearest thing
10 pure color photography that has been
achieved, and he INDICATED his theory, but any
practical application OF his methods 10 general
purpose i out Of IN" question. Tho process is
con pliCated and difficult, and multi
plication of tho. photographs obtained is im-
po~si'l To-, s" t"w impressions were made by his
method, and these few With great expenditure
of time, work and money.
The success Of this method depended upon tho
same principle that explained The reprodnc-
ton oi color in muriaie of silver Tho inter-
terence oi light waves, through reflection. Limp
man put Il tram parent, highly sensltized film
IN iinnc!ial" contact With 2 mirror hacked with
mercury Light passing through the flm WIS
reflected back along the same line by the mir
ror, Advancing light waves and reflected light
waves, meeting under certain conditions, can
col or neutrali1c one anOthcr, the result being
white light minus these cancelled waves-that
j., "olored light. color waves differ I'M wave
length according to the different lines 81 the
spectrum. 80 the conditions under which the
direct and reelected waves meet vary according
10 their color, and The film records this variancs.
The white light entering tho camera has been
lighf being composed Of all the hnes If tho
spectrum and, when 'he rim is agnin exposed
In white light. IL shows the impression received
in oOlors ono Crent disadvantage of these
Iippnan photographs l. thai tho white light
mus, fall upon IA" "ompIe'ed rim at a certain
angle in order ~ give the color effect. Seen at
any other angle III" photographs look like
| ~CnlorleSs negatives.
The only practical success in color photo0-
raphy So far,has been accomplished by indirect
methods, and. though these processes may not
no so interesting from IN" viewpoint Of abstract
science a. The lippman process, their commer-
cial value is innniinlv greater. Indirect color
photography primarily consists in The produce
ton Of three SEPARATE negatives, taken through
screens Of the three primary COlor>, red, green
and blIe, and IN the optical Superposition II
these images. but there have been innumerable
derelopmentS Of this Process, The, original
composite color photographs. requiring three
separate negatives obtained by three separate
exposures and three separate r~ositiyes pro-
jeCted by a single lantern. was too cumbersome
and complicated TO 10 practicable. A great
effort has been made 70 bring the process into
such shal" that il could he easily accomplished
~ h. IA an tnt = md fhn q nm attt= . rnt-
for II carried rs easily as the ordinary camera.
No such conditions have been attained. but q
good deal has been accomplished aud tbs
photochronoscope. with It's more recent devel-
opments, the kromskoD, is thought by scientists
10 come as near a solution OF the problem 40
anv OF the later inventions.
Ry this photochromosCope process the three
negatives ara taken upon n single sensitive
plate at one exposure. and the contact positive,
cut into three SECTIONS with scissors and mounted
upon n folding cardboard, ~ dropped into tbs
pho~tochromoscopo v hich, a. we'll as the camera.
may he made s'"reoscOpic, the size of the ordi-
nary hand ster"oscope. The camerai Eliminates
three C0lOrleSs transparent p~osiiives separately
hv lights of the three primary tlnts, and these
impressions are opticallv rec0mhined into ona
colored image in the seeing apparatus q rphoto>
chromoscOpe. or course, this seeing instri~
mentis necessary 10 carry out the sense Of color.
50 the process l. far from being the one long
desired. which j. 10 produce cOlOred prints thai
NAV be framed and hung on the wall, Through
This viewing device, however. color images Of
maryellous fidelity are obtained, giving al!
aualitins Of texture, sheen, translucency and
atmosphere to a degree impossible 10 any color
print on parer, Pictures Of the old masters
can h. reproduced aud seen in the photochromoS
scope with all their original qualities. Sciens
tin" objects, specimens for natural history
collartionS, beauties Of landscape. botanical
specimens. tapestries and textile fabrics Of all
kinds may be studied through these color im>
ages ~ satisfactorily a. from reality. The
color records take mp No more room than ordiS
narr photographs, and If the cost and difficulty
Of the production ran be decidedly reduced this
form Of color photography NAV he utilized IN
great advantage in schools. in medicine. in
many Of the other sciences and in commercial
business. where II could represent the quality
and appearance Of goods more satisfactorily
than any print or irHgmentary sample. C0lS
ored photographs Of the most beautiful species
81 butterflies have been among the greatest
triumphS II this process and not the smallest
element Of the beauty Of the original is lacking
in tho reproduction, The miniature kromskop
Is the latest and simplest development OF the
apparatus and j. less expensive than the original
INSTRUMENT,
Another method Of color photography finding
great favor to-day applies the same principles
in another way. The hight l. projected upon
the plate. not through three screens, bur through
one screen closely ruled in orange. green and
violet. These lines are ruled OF. geiatine plates
in pigments made up a. inks. and these are from
500 to 900 10 the inch although when the lines
exceed 400 To the inch the eve ceases 10 be an
moved bv them. The resultant lines upon tho
positive register, Of course, the degrees IN which
the three color sensations would have been
produced. Then n second screen. ruled in red.
green aud violet. and gagged exactly VI accord-
- iii a.. a. - LL.s.l -,aa. thn IA