The illustrations show the method of operating the
baffle over the photo-electric cell. When the baffle is
closed, the high light scale (0 - 1600) moves into
position. The baffle should be kept closed when the light
reads 25 or higher. If the light reading is less than 25,
the baffle should be opened bringing the low light scale
(0 - 25) into use.
Hold the meter as shown here, being careful not to
obstruct the photo-electric cell with your fingers or the
neck cord. For outdoor general scenes, when the reading
is taken from the camera position, tilt the meter
sufficiently downwards to avoid measuring sky areas which
would inflate the reading and cause under exposure. The
required degree of tilt is dependent upon the scene.
1. Set the film exposure index by moving the
Exposure Index Knob until the Exposure Index number
(ASA Index) of your film appears in the Exposure Index
window.
2. Aim the meter as described in Aiming
the Meter
On/Off Pointer Lock
By sliding the pointer lock to the left, the
pointer will be locked at the reading; sliding the
lock to the right releases the pointer. The meter must
be held steady when operating the lock otherwise a
false reading may be obtained. When the meter is not
in use, the pointer should be left unlocked.
3. Transfer the light reading by turning the large
knurled outer dial until the Normal Arrow is opposite
the reading on the Light Scale of the Calculator
Dial.
4. Set your camera with any combination of shutter
speed and f/stop indicated. Any combination of shutter
speeds and f/stops opposite each other on the
Calculator Dial will give the same correct exposure.
The combination selected will depend on whether you
want a fast shutter speed with a large aperture (low
f/stop number) to arrest action; or greater depth of
field calling for a smaller aperture (high f/stop
number) and a slower shutter speed.
Exposure Value Numbers
For cameras calibrated in Exposure Values, set your
camera to the exposure value number appearing in the
Exposure Value Window.
Classification
of Scenes
It will simplify the classification of scenes to
remember that the exposure meter measures the average
in brightness value of the scene. Thus for normal
exposures the arrow position on the Calculator Dial is
used. However, for those scenes requiring less or more
than the normal exposure the 'A' or 'C' positions may
be employed, where half or double normal exposure
respectively is required.
The following recommendations apply primarily when
monochrome negative film is being used. See Colour
Photography section.
Flat scenes lacking in contrast, such as distant
views and landscapes on dull days, generally require
less than normal exposure and more than normal
development for best reproduction. Set the 'A'
position on the calculator dial opposite the light
value measured for such scenes, thus halving the
exposure.
The contrasty scene, such as a sunlit street with
dark shadows, for best reproduction requires more than
normal exposure and less than normal development. Set
the 'C' position on the Calculator Dial opposite the
light value measured for these scenes, thus doubling
the exposure.
Remember, however, that about eighty per cent of
all scenes require a normal exposure and when in doubt
about any scene, use the arrow position on the
Calculator Dial.
Camera
Position Method
The normal method of use of the meter is at the
camera position, i.e. close to the camera. It is a
simple method and the one most frequently used. This
method gives a correct exposure for the average scene
and does not isolate any particular object from an
exposure point of view.
Take a light reading (avoiding sky areas) and set
the Calculator Dial as already described. Chose a
combination of f/stop and shutter speed consistent
with the subject to be photographed.
Generally, the arrow position on the Calculator
Dial should be used. For flat scenes, or for scenes
with extreme contrast of highlights and shadows, use
the 'A' or 'C' position as described in Classification
of Scenes.
The camera position method should not normally be
used for back-lighted snow, sand or water, since
spectacular reflections can result in under exposure
of the shadowed areas. See also Backlighted
Subjects.
But for landscapes, general views and other
photographs where a quick reading is wanted, the
camera position method is quite satisfactory.
The Close-Up
Method
In the Close-up Method the meter is held close to
the subject being photographed. By doing this, the
effect of the background is minimised and the film
exposed for the main centre of interest.
Hold the meter close to the principal object,
making sure that no light reaches the cell from
unimportant parts of the scene.
When taking a reading, be sure that you do not cast
a shadow on the subject. To avoid this, the meter may
have to be held at an angle to the direct light on the
subject, i.e. you can measure the reflected brightness
by standing slightly to one side.
Having taken your close-up reading set the
Calculator Dial to the arrow position and make your
camera settings.
The above method is not recommended where the
picture contains large light areas and relatively
small but important dark areas. Additionally, when
using this method for colour photography, it is
equally desirable that there shall be no small but
important light areas in an otherwise dark scene.
Brightness
Range Method
The Brightness Range Method consists of measuring
the light values of the lightest and darkest objects
of the scene and thereby centering the exposure
between the two extremes.
In any scene, various objects reflect different
amounts of light. To produce a good photograph, all
objects should be correctly exposed and thus the
extremes of brightness should be measured.
Take a close-up reading of the darkest object in
the scene (for example, a dark hedge) and note the
light value. Then make a close-up reading of the
brightest object (for example, a white wall) again
noting the light reading.
Set the arrow on the Calculator Dial midway between
the darkest and brightest object light values, i.e.
the arrow should be the same number of divisions or
blocks from the darkest light value as it is from the
brightest.
You can then read off a suitable combination of
f/stop and shutter speed for the scene, or
alternatively, the exposure value.
Most monochrome negative emulsions can record a
long range of deep shadows and bright highlights in a
single negative. A knowledge of the limits of this
range can prevent unnecessary loss of detail in
extreme shadows or highlights when long range subjects
are encountered.
The 'U' and 'O'
Positions
The 'U' and 'O' positions on the Calculator Dial
show the recommended limits of subject brightness, the
ratio of these being 128:1. For a given setting of the
dial, all objects whose light values fall on or
between these two limits will be correctly exposed.
Any object having a light value below the 'U' position
will be under exposed and any object with a light
value above the 'O' position may be difficult to
reproduce.
By setting the 'U' position opposite the darkest
object light value, the indicated exposure will be
just sufficient correctly to reproduce that part of
the scene.
Where the overall brightness is of a low order,
such as a dark hall or cave, it might be impossible to
obtain a reading from anything but a very bright
object. If the 'O' position is set opposite this
bright object light value, the indicated exposure will
avoid over exposing the highlights.
Where the brightness range of the scene exceeds a
ration of 128:1 use of the 'U' position may involve
some sacrifice of detail in the extreme highlights.
Conversely, use of the 'O' position will cause loss of
shadow detail.
Substitute
Readings
It is not always convenient to take close-up
readings and in such cases, substitute readings of
nearby similar objects may be made, but ensure that
the lighting is the same and that the objects are
similar.
Highlights
and Shadows
In a scene such as that shown above, the brightness
range greatly exceed the film range i.e. the patches
of sunlight may give a light reading of 500 and the
deep shadows a reading of -2. The average film range
if thus not wide enough to give printable details in
both the highlights and shadows, although a good
average exposure can be obtained by using your meter
as already described. According to the effect you
require, however, you can choose to expose for details
in the shadows by using 'U' position or,
alternatively, for detail in the highlights by using
the 'O' position. See The 'U' and 'O' Positions. The
foregoing is particularly true of short range, slow
film. Many films, however, have a range greater than
128:1 and when using such material, use of the 'U'
position is often preferable.
Colour
Photography
Until experience has been gained, avoid extreme
lighting conditions and allow the color to provide the
contrast. For outdoor shots, if possible expose
between 10 a.m. and 3 p.m. as the quality of the light
is normally best during this period. If the sun is
shining it should be behind the camera. Watch the
reflection values of the surroundings i.e. a white
dress can be turned pink from a red object reflection.
Avoid shadows and subjects in shadow, as these are
illuminated by skylight which is more blue than
sunlight, for which the film is balanced. An ideal
scene is one having low contrast and even
illumination. Best results are obtained on a clear
sunny day.
Colour
Film Range
The range of scene brightness which can be recorded
on colour film is far more restricted than that of
monochrome material, the ratio being in the order of
30 to 1. Therefore the brightness ration in general
should not exceed this figure.
For best colour rendering it will generally be
found that the light value range of extreme colours
will lie between the dot positioned one whole stop
above the 'C' position and the dot positioned one
whole stop below the 'A'. Objects whose light values
lie outside this range may suffer in colour rendering.
Effective pictures in colour are obtained from colour
contrast rather than from highlights and shadows as in
monochrome photography. The method recommended is the
Brightness Range Method.
First take a close-up reading of the darkest colour
in the scene. Then take a close-up reading of the
brightest colour. Set the arrow position on the
Calculator Dial midway between these light values and
make your camera setting.
The above method locates the exposure in the middle
of the film range and is suitable for the average
subject in flat lighting. If the darker colours are of
principal interest, a longer exposure may be
preferable. Conversely, if the brighter colours are of
interest then shorter exposure may be necessary.
It must be appreciated that varying the exposure to
suit one end of the colour range may affect true
rendering of the other. A useful suggestion is to use
the 'C' position when exposing for the darker colours
and the 'A' position for the brighter colours.
Correct exposure will, of course give the best
results but if in doubt, remember that slight under
exposure gives better colour rendering than over
exposure. With negative/positive colour processes,
however, the opposite is the case and slight over
exposure is preferable to under exposure. In both
forms of colour photography, it is normally desirable
to avoid shadows and extreme contrast in lighting.
When the same scene contains large areas of a light
tone, normal use of the meter will result in an
inflated reading and consequent under exposure. In
such cases a reading should be taken of an average
portion of the scene, avoiding the areas of light
tone.
Cine
Photography
A cine camera is essentially the same as a still
camera except that it exposes a series of pictures at
a fixed shutter speed. For cine work the Brightness
Range Method is recommended.
Make close-up readings of the darkest and brightest
objects in the scene and set the arrow position midway
between the light values obtained. The correct f/stop
to use will then be found opposite the particular
shutter speed of your cine camera.
The standard number of frames exposed by the
average amateur cine camera is 16 per second (now
18 for silent and 24 for sound ) at a shutter
speed of 1/30th second. For other frames per second
than 16, the shutter speed is proportional. Use the
settings shown in the following table:
8 frames per second 1/15th
16 frames per second 1/30th
24 frames per second 1/50th
32 frames per second 1/60th
48 frames per second 1/100th
64 frames per second 1/125th
Some cameras may have a different shutter speed at
16 frames per second, such as 1/40th or 1/50th and the
f/stop for these should be read off against this
shutter speed on the Calculator Dial. If the shutter
speed of your camera is unknown, ascertain it from the
camera manufacturer.
Backlighted
Subjects
If the meter is aimed directly at a back-lighted
subject, i.e. one where the main lighting comes from
behind, it is obvious that the light value reading can
be inflated resulting in under exposure.
To overcome this, turn around and take the reading
on a similar object with your back to the lighting so
that your body casts a shadow on the substitute
object.
For example, in the picture above a close-up
reading could be made of a handkerchief for the girl's
blouse, ensuring that the substitute object is in
shadow.
For all beach scenes, light readings should be
taken with the sun over your shoulder. Direct
reflections from sparkling water should be avoided
when taking light readings.
Additional
Notes - Still and Cine
High Altitudes Films are sensitive to
ultra-violet radiation, of which there is a
considerable amount present at high altitudes. To
eliminate the effect of this, it is always good
practice to use a haze or ultra-violet filter. No
exposure correction is necessary so use the meter in
the normal manner.
Snow, Beach and Water Scenes. Take readings
of the brightest and darkest objects and set the Arrow
midway between, or take a reading from the palm of
your hand and use the 'C' position on the Calculator
Dial. The best rendering of snow texture results when
the snow is back or cross lighted.
Copy Work. When copying pages of a book or
photographs in black and white or colour, take a
reading from a white card placed over the subject.
Divide the exposure index by five and set this value
in the Exposure Index Window. Set the Arrow at the
light reading obtained and select the camera settings
in the usual manner.
Television. Adjust the television screen for
high contrast. Place the camera on a tripod, set the
shutter at 1/25 second and focus on the lines across
the screen. Dim the room lights. Take a close-up
average reading holding the meter about six inches
from the screen. Set the Normal Arrow at this reading
and select the camera settings in the usual
manner.
Sunsets and Sunrises. Aim the meter directly
at the subject and set the Normal Arrow at the
reading.
Aerial Pictures. To prevent the sky from
inflating the reading, aim the meter down towards the
ground. As a general guide, below 1,000 feet use the
meter reading indicated; from 1,000 to 2,000 feet set
the Arrow on the Calculator Dial one space higher than
the meter reading, thereby reducing the exposure by
1/3 f/stop; from 2,000 to 4,000 feet, set the Arrow
two spaces higher than the meter reading (an exposure
reduction of 2/3 f/stop). Above 4,000 feet, set the
'A' mark instead of the Arrow to the meter reading (an
exposure reduction of one f/stop). If no other filter
is in use, a skylight filter, haze filter or
ultra-violet filter should be used, in which case no
exposure correction is required.