CAUTION
Never attempt to work backwards through
the sink-line process. A few drops of fixer on
your hands or from a print will contaminate the
developer.
PROJECTION PRINTING
LEARNING OBJECTIVE: Recognize the
purpose of projection printing, identify the
main difference between projection and
contact printing, and summarize the
advantages of projection printing.
Projection printing is the process of making positive
prints by projecting the negative image onto
photosensitive paper. The projected image may be
enlarged, the same size as the negative image, or
reduced in size. When the print images are larger than
the negative images, the process is called enlarging.
When the print images are smaller than the negative
images, the process is called reducing. Because
projection printing is usually used to make positive
prints with images larger than the negative, projection
printers are usually referred to as enlargers. The term
enlarging generally refers to all forms of projection
printing.
DIFFERENCES BETWEEN PROJECTION
AND CONTACT PRINTING
Projection printing differs from contact printing
because the negative is separated from the paper and the
image is projected by a lens onto the sensitized material.
The negative is placed between an enclosed light source
and a lens. The lens receives the light that passed
through the negative and projects the image onto the
paper. Changing the distance between the lens and the
paper controls the size of the image. The image is
focused on the paper by adjusting the distance between
the negative and the lens. It is possible to enlarge or
reduce the size of the projected image by changing and
adjusting these distances.
Enlarging is a very adaptable and versatile process
because considerable image and exposure control can
be used The main advantage of enlarging over contact
printing is that large prints can be made, but there are
several other important advantages. The advantages of
projection printing areas follows:
l Cropping (selecting the main area of interest
in a negative) can be done and enlarged to any
l
l
l
l
suitable size. This gives you the opportunity to
eliminate unwanted and distracting elements
from around the point of interest of the picture.
Dodging or burning in. This allows you to apply
local exposure control to bring out more detail in
the highlight and shadow areas.
Local fogging with a small external light, such
as a penlight, to darken selected areas. For
example, to darken the background of a portrait
to direct viewer attention to the face.
Special effects. You can change the appearance
of the image by use of diffusers or patterns
between the lens and paper.
Image distortion correction or introduction
can be done by tilting the enlarger easel. An
easel is the device used to hold the paper during
exposure.
ENLARGERS
In general, all enlargers are similar in design and
operation. They have an enclosed light source, some
method of providing an even distribution of light over
the negative, a negative carrier, a lens, and a means of
adjusting the lens-to-negative and lens-to-paper
distances. There are two types of enlargers —condenser
and diffusion.
Condenser Enlarger
The condenser enlarger (fig. 11-32) is the one most
commonly used in Navy imaging facilities. It has a set
of condensing lenses between the printing light and the
negative. These lenses align and project the light rays
evenly through the negative. Since all features of the
negative are being enlarged, any flaws also will be
enlarged.
Diffusion Enlarger
The diffusion enlarger (fig. 11-33) has a diffusing
medium (usually a ground glass) between the light
source and the negative to spread the light evenly over
the entire surface of the negative. Light emitted from the
lamp, as well as that reflected from the parabolic
reflector, strikes the diffuser, which, in turn, scatters it
in all directions. Thus, when the light reaches the
negative, it is traveling in a nondirectional pattern.
Most enlargers have a tungsten lamp as a light
source. The lamp is enclosed in a lighttight housing that
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