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Composite Portraiture
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exposure of eighty seconds to give an exact photographic copy of any one of them. The
general principle of proceeding is this, subject in practice to some variations of detail,
depending on the different brightness of the several portraits. We throw the image of each
of the eight portraits in turn upon the same part of the sensitised plate for ten seconds.
Thus, portrait No. 1 is in the front of the pack; we take the cap off the object glass of the
camera for ten seconds, and afterwards replace it. We then remove No. 1 from the pins,
and No. 2 appears in the front; we take off the cap a second time for ten seconds, and.
again replace it. Next we remove No. 2, and No. 3 appears in the front, which we treat as
its predecessors, and so we go on to the last of the pack. The sensitised plate will now have
had its total exposure of eighty seconds; it is then developed, and. the print taken from it is
the generalised picture of which I speak. It is a composite of eight component portraits.
Those of its outlines are sharpest and darkest that are common to the largest number of the
components; the purely individual peculiarities leave little or no visible trace. The latter
being necessarily disposed equally on both sides of the average, the outline of the
composite is the average of all the components. It is a band and not a fine line, because the
outlines of the components are seldom exactly superimposed. The band will be darkest in
its middle whenever the component portraits have the same general type of features, and
its breadth, or amount of blur, will measure the tendency of the components to deviate
from the common type. This is so for the very same reason that the shot-marks on a target
are more thickly disposed near the bull’s-eye than away from it, and in a greater degree as
the marksmen are more skilful. All that has been said of the outlines is equally true as
regards the shadows; the result being that the composite represents an averaged figure,
whose lineaments have been softly drawn. The eyes come out with appropriate
distinctness, owing to the mechanical conditions under which the components are hung.
A composite portrait represents the picture that would rise before the mind’s eye of a
man who had the gift of pictorial
