projected image warrants a greater distance bet-
ween the lens of the enlarger and the receptive sur-
face than is manageable with an enlarger that
projects downward.
An enlarger’s lamphouse contains the light source
used to make the exposure. Various enlargers
employ different types of light sources, including
tungsten, quartz-halogen, and fluorescent. Color
printing requires that the light source be accessible
to color filtration. There are some enlargers that are
specially designed for color printing, and have dial-
in color and density combinations made available
through built-in gelatin or dichronic filters. A few
color enlargers employ three differently-colored
light sources to make three separate exposures
onto the paper: one in red, one in blue, and one in
green. In any enlarger, the light source is directed
through either a condenser lens or a diffusion screen
onto the negative, which is held in place by some
type of negative carrier.
The negative carrier is generally one of two types:
dustless or glass-sandwich. The dustless type of nega-
tive carrier is two plates of either metal or plastic with
holes cut for the particular size of film negative being
used. The plates hold the negative in position by its
edges. Dustless negative carriers are available for
film sizes ranging from subminiature to large-for-
mat, though are most often used for 45-inch and
smaller negatives. Glass-sandwich negative carriers
are made of two solid plates of glass, which press the
negative flat. These negative carriers are most often
used for large-format negatives, which tend to sag or
droop in the center if not properly supported.
The light from the lamphouse is distributed
evenly across the negative, which leads to equal
distribution across the surface of the photo-sensi-
tive material. After passing through the negative,
the light enters a bellows and lens, where the photo-
grapher may control the focus of the image onto
the photo-sensitive material. The bellows should be
capable of being opened to twice the focal length of
the lens, which will allow for 1:1 reproductions of
the negative. If a print smaller than the size of the
negative is desired, a longer focal-length lens or a
special reducing attachment is required.
Degrees of enlargement of a negative are
restricted by the structure of the enlarger and the
size of the paper. Occasionally, a photographer
might be interested in making a print larger than is
possible with the fixed space between his enlarger’s
lens and baseboard. There are ways around this
limit, including removing the baseboard and affix-
ing the enlarger to something stable, as a table or
bench, and then projecting the image onto the floor
(which should greatly increase the distance between
lens and photo-sensitive material). Some enlargers
allow for the possibility of the head being turned
around 180(which would also facilitate projecting
the image onto the floor or some other lower-than-
baseboard-height base); these should be stabilized
with something heavy to offset the weight of the
head, which is suddenly insufficiently supported by
the vertical column or girder assembly. Others come
equipped with heads that pivot so that the lens is
parallel to a vertical surface (such as a wall); the
negative is then projected horizontally onto this
vertical surface. The enlarger can be moved farther
away or closer to the wall to achieve the desired
enlargement size.
There are also practical considerations of en-
largement: after a certain point, even the most well-
developed and high-grade negatives will begin to
show grain when enlarged overly much. If enlarged
full-frame, 35 mm negatives begin to show grain and
lookout-of-focuswhenenlargedmuchmorethan8
10 inches, and 120 film negatives begin to show grain
and look out-of-focus when enlarged much more
than 1620 inches. If only a small area of a negative
is enlarged, considerations should be made as to the
maximum size of possible enlargement that will still
maintain crisp focus. Even so, the graininess that
results from over-enlargement of negatives can be
appealing to some photographers.
Most enlargers have both rough- and fine-focus
controls. The rough-focusing control moves the
whole enlarger head (which is comprised of the
lamphouse, the negative carrier, the bellows, and
the lens) up or down the vertical column or girder
assembly that supports the head. Rough-focusing
allows the photographer to determine the size of
the projected image on the enlarger’s baseboard.
Some enlargers have automatic rough-focusing
controls that allow the photographer to move the
head of the enlarger with the press of a button
rather than by manually turning a crank.
Focusing the negative takes place before the
photo-sensitive material is placed underneath the
lens of the enlarger, as it requires the photographer
to turn on the enlarger light. The rough-focus is
determined without a focusing aid, and is used to
ensure that the enlarged negative is not larger than
the area available on the light-sensitive material.
The rough-focus also allows the photographer to
get the negative as close to focused as possible
before relying on the fine-focus control. Once the
rough-focus control is set, the photographer uses a
focusing aid to complete the focusing with the fine-
focus control. The fine-focus control actually moves
the bellows between the negative and the lens to
achieve clear focus.ENLARGER