Download Report - Academy of Motion Picture Arts and Sciences

Carbon Arc and Incandescents in the studros tn
regard to the tests, summaries of which were shown
lai Tuesday night. This is a summary week.
Tomorrow nighi results will be given and I
should like to urge the discussion of the paper in
reference to these practical tests. I would like to
ask Mr. Downs of the specific efrciency o{ the arc,
that is, what proportion of its energy is dissipated
as heat a.td what percentage is dissipated as light?
Mn. Dowxs: The distribution of energy dissipated
in the case of the White Flame Arc is 4 p-er
cent up to 4000 Angstrom units or. below the
visible, 30% in the visible region and 667o beyond
the 7d00 Angstrom unit, that is in the infra-red'
The distribution in the case of the Panchromatic
"O" Arc is 4 per cent up to 4000 Angstrom units
or below the visible, 32 pet cent between 4000 and
7000 Angstroms or in the visible and 64 per cent
above 70"00 Angstroms or in the infra-red' The
distribution in the case of a q\artz-mercury arc
is 9.0 per cent up to 4000 Angstrom or-below the
visible, 9.0 per cent between 4000 and 7000 'Angstrom
or in the visible and 82 per cent above 7000
Ansstroms or in the infra-red. We have been told
heri that over 90 per cent of the energy of the incandescent
lights is dissipated in the infra-red
region above 7000 Angstroms.
Mn. Wrr,r,rnono: I would like to ask if in any
of the Academy tests any Panchromatic Carbons
have been used. All have been White Flame that I
have seen. I am just wondering i{ any of the cinematographers
ran any of these tests with panchromatics
?
Mn. Dunnav: I think that test No. 8 was shot
with Panchromatic Carbon. Mr. Handley will perhaps
remember better than I do which one o{ the
tests was photographed with these panchromatic
carbons. There were very few but I believe one set
of closeups can be found in the first reel.
Mn. Guv WrrrY: We have been told that
very little of the energy used goes toward heat. Is
there any way we can find out the comparative
percentages for Arc lights, Mazdas and Cooper-
Hewitts ?
Mn. DowNns: The infra-red region above 7000
Angstrom units is that region in which the heat rays
are produced. The percentage of energy dissipated
of the white llame carbon arc in the heat region
above 7000 Angstrom units is 66 per cent, of the
Panchromatic "O" Carbon Arc is 64 per cent, of
the Quartz Mercury Arc 82 per cent, and as we
have already been told here, the proportion of the
energy in this region for the incandescents is over
90 per cent.
Mn. Joxrs: I noted one thing in looking at
the tests run at the Chamber of Commerce on
Tuesday evening, under both Arc and Incandescent
the lips seemed light. It is difficult to draw definite
conclusions without knowing exactly the characteristics
of the make-up used. But we have very good
evidence that with the Orange Flame Carbons, and
also with Mazda illumination, lips without any
make-up will photograph somewhat too light. It
is also probable that the bright red make-up used on
the stage will photograph too light. This shows that
we ate probably obtaining appreciable over-correction
when using Mazda illuminatiou with the present
high red sensitive panchromatic film. As was
brought out last night, it appears that the manufacturers
of make-up materials have already met this
situation and that a lip rouge which is brown in
color has been developed for use under Tungsten
illumination. This of course takes care of this particular
condition but we must remember that other
red objects in the set will also be somewhat overcorrectid.
One other fact which r..-.d pronounced
to me was the lack of any brightness differences
across the cheeks and faces. I do not know anything
about the make-up which was used when these shots
were made, but if there was any trace of pinkness or
redness in it, it was entirely washed out by the illumination
and film. I cannot help but feel that a
certain amount of brightness difierence across these
areas would more nearly simulate a lifelike appearance.
Of course before panchromatic film was available,
all red tended to render as black and hence
blood vessels and facial blemishes were enormously
exaggerated, and it was necessary to adopt a technique
which would eliminate this distortion. I
believe that with the panchromatic film and the
relatively red illuminants, it should be possible to
retain some of the skin and flesh texture with the result
of achieving a more natural reproduction of faces.
Mn. Bar,l: Mr. Dubray is most familiar with
these tests. Was any rouge used on the cheeks ?
Mn. Dusnay: No rouge was used on the
cheeks. In fact, we always eliminate rouge on the
cheeks because in most cases it gives the impression
of a sort of shadow or dirt instead of colorine. The
texture of the skin looks more pure without any
change in its tones than if we tried to give this
impression of red coloring. This is perhaps due to
the dificulty of photographic control of such shades.
As to the matter of rouge for the lips, I would
point out that during the tests made at Warner
Bros. studio we have been experimenting on this
subject so the proper rendition of color of the lips
will be noticed in the tests which bear a higher
number made during the last days of testing. I do
not know exactly at which number the best rendition
starts. It may be 50 or perhaps 55. The
majority of the tests have a tendency to show the
lips too light.
Mn. Ban: Dr. Lamar Lyndon is present. I
wonder, Dr. Lyndon, if you could make some remarks
about the use of Incandescent and Arc lamps
in the studios?
PAPER BY
DR. LYNDON
Dn. Lal,ran LyNooN: I have made some recent
investigations of one factor of the Tungsten
lamp which refers to the matter of the most economical
period of use of these illuminants.
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