Camera Work: A Photographic Quarterly (1906 (Heft 13))

WHEN we every day see photographs in which all

Now, what is meant by the word focus? Focus is generally understood
to mean the bringing together of dispersed light into one clear image by
means of a lens or concave mirror, etc. The object of focusing is to spread
upon a surface an image of matter in space, so that we may at our leisure
examine and see what is existing in the world outside of us. The camera
has greatly the advantage over the eye in focusing, as it is able to produce
well-defined shapes of equally distant objects at one and the same instant
over the whole negative, but the retina of the eye is properly sensitized on
only a very small part of its surface, a mere point, and to at all gain a clear
But rapid as these kinesthetic movements are, the multiplicity of detail
in nature is so enormous that more than an appreciable length of time is
required before the retinal image of an object can be completed. What will
take the camera the one-hundredth part of a second to accomplish, will take
the eye one hundred seconds, or maybe as many minutes. And, further,
the eye fatigues easily and saves itself whenever it can, and, unless it is
especially interested, will bring clearly into its field of distinct vision but few
points of what it is examining, the result being that a really somewhat blurred
picture is presented to the mind. It was these shortcomings that made
Helmholtz cry that " if an optician were to furnish us with an apparatus as
poorly constructed as the eye we would throw it on the rubbish-heap."
journal that you have not read and quickly fix your eyes on one word, hold
them there, and see how many lines above and below will be distinct. How
many words to the right and to the left can you read? Yery few; not because
the lens of the eye does not throw a clear image of the whole page on the
retina, but because only a small part of the retina is adapted to understanding
sharp focus, the rest feeling but vaguely. Therefore, to understand the full
page, the eye has laboriously to direct its sensitive point toward every part.
To see completely, even as familiar an object as a head, we must search it
over and over again.
However, it is through the virtues and weaknesses of the eye that we
know and recognize nature, and if the photographer wishes to make us
believe that his photographs look like nature, he must subordinate the
virtues of his superbly constructed machine and force it to imitate the defects
the eye one hundred seconds, or maybe as many minutes. And, further,
the eye fatigues easily and saves itself whenever it can, and, unless it is
especially interested, will bring clearly into its field of distinct vision but few
points of what it is examining, the result being that a really somewhat blurred
picture is presented to the mind. It was these shortcomings that made
Helmholtz cry that ccif an optician were to furnish us with an apparatus as
poorly constructed as the eye we would throw it on the rubbish-heap.,,
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know and recognize nature, and if the photographer wishes to make us
believe that his photographs look like nature, he must subordinate the
virtues of his superbly constructed machine and force it to imitate the defects

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