Evening star., 1950-11-12
Camera Angles
Color temperature Is Important Factor

In previous discussions we have
gone into the physical makeup of
color film and we have seen ex-
actly what happens to the color
medium during the course of proc
essing. We will go a step further
now and take up the subject OF
color temperature.
Color temperature is quite bit
different from the kind Of which
we are accustomed to thinking
the kind that will make us put
on an extra coat one day and
take it off the next. The kind OF
temperature that interests us to-
day is that Of light-natural and
artificial. The light that comes
from the sun or is shed from q
fioodlamp has color temperature
as well as temperature that can
be measured in degrees of heat,
We have been accustomed to
measuring temperature with a
Fahrenheit or Centigrade ther-
mometer. Now, if we are to get
the best from our color film, we
must learn something of the other
kind of temperature that is meas
ured by color temperature meter
in degrees Kelvin.
Kelvin Is just a name applied
to scale by which we can meas
ure the color quality of light. We
will see that the color temperature
of naturM light Chat which comes
from the sun and sky) varies con-
stantly. And because of this, If
you do not have a working knowl-
edge Of the application of color
temperature to color photography,
your color shots will vary in quail
ity In direct proportion to your
lack Of understanding. On the
other hand. artificial light color
temperature is more or less under
the control Of certain factors. The
color quality Of artificial light de-
pends upon the temperature of
the f1lament which in turn is gov
erned by the voltage at which the
lamp is operated.
Lamps Rated by Temperature.
You have probably noted by
comparison that the ordinary
reading lamp emits a yellowish
light while Photographic flood
lamp appears to be much whittier.
Lamps that are used In photo
graphy are rated according to
their color temperature, a fact
that is, little appreciated by the
beginner in color work. In fact
a surprisingly large number of
amateurs do not take color tenn
perature into account at all when
exposing color film. From this it
Is easy to gather that much of
the color work that goes to the
professor is hit or miss collec-
tion of exposed film only a por-
tion of which turns out well be-
cause of extreme care taken in
processing.
To take care of this problem of
differences in the color temper
atures of various types of light
available to photographers the
manufacturers of color film have
hit upon the happy solution of
providing color films that are de-
signed to meet each different
light condition. For instance in
the case of Kodachrome films,
daylight Kodachrome is color
balanced to the color temperature
of the daylight encountered dur
ing most of any normally sun
shiny day. This light condition
features an amount of light from
an overhead sun plus additional
light coming from a blue sky. The
color temperature of this normal
daylight is about 6,100- degrees
Kelvin. But with the sun Just
coming up or going down or with
interference from clouds or from
other sources, it is apparent that
the color temperature of the light
will be different. Failure to take
this into account is the cause of
80 many failures and unusual
effects seen in color photography
by some amateurs.
Another type color film (Type
A Kodachrcme) Is color balanced
to the color temperature of photo
f1oodlamps which, on lis volt
lines, have a color temperature of
3,400 degrees Kelvin. This type
of artificial illumination is lack
ing in blue-violet and yet is over
abundent in red-orange and con-
sequently needs a film that is very
sensitive to blue-violet to COM
pensate for this condition. And If
tungsten lights are used as an
tlluminant, still another film
Kodachrome Type BIS color
balanced to 5000 Kelvin to COM
pensate for the inherent peculiar
tiles Of this lights color temper
ature.
Color Balance Required.
This may clarity the reason
whv you cannot load your camera
with any type of color film and
shoot it under any lighting con-
diJion and still have good trans
parency as a result. Knowing
that lights of different sources
have different color characteris-
tics is the key to the problem.
Pictures can be taken with day
light film and artificial light and
types A and B film will record
pictures out-of-doors, but in
either case the color balance will
be so far off that the exposures
will be virtually worthless.
What would happen, for in
stance, If daylight film is used
with flood or tungsten lights is
this: Reds and orange would be
predominant with intense reds,
olive looking green's, brownish
blues and orange yellows and
whites. Or, If Type A or B film
was exposed out-of doors, blue
would predominant with red OBJ
jectS appearing a deep crimson