Page 125 - The Wellington photographic handbook

hint can be given, as it depends on the character of the negative
the strength of the light, the degree of reduction and the stop in
the lens, the camera is carried back and the plate developed. Other
forms of fixed-focus reducing cameras are provided with a dark
slide, so that it is not necessary to carry the whole apparatus into
a dark-room for loading. Other lantern slide cameras are so
arranged that the negative can be focussed, and any desired degree
of reduction obtained.
Slides may be made by reduction without any special apparatus
other than an ordinary camera provided with a carrier to take a
lantern plate. The negative to be reduced must be fixed in front
of an opening in a piece of wood or card, so that the surrounding
light is cut off from the camera, and the negative is illuminated
from behind. This may be done in daylight by fixing a white
card, larger than the negative, at an angle of 45° behind it, and
placing the whole arrangement where the light from the sky can
shine down on the card. Or artificial light may be used. A
paraffin lamp or a gas burner with a big ground-glass globe makes
an excellent illuminant for a quarter-plate, but with larger sizes
something more elaborate is necessary to get even illumination,
One of the simplest plans is to take two pieces of fine ground glass,
an inch or two each way larger than the negative, and to fix them
one inch apart from each other and the nearer one at least one
inch behind the negative. Almost any illuminant can be used
behind such an equaliser. Incandescent gaslight does very well,
or magnesium ribbon may be burnt. In front of. the negative
the camera is set up, and the image sharply focussed on the screen
to the required size. A WELLINGTON Lantern plate is
then put in the slide and exposed.
It is well to note that the camera and negative should, prefer-
ably, be supported on the same board or table, to prevent inde-
pendent movement, which would cause blurring. The focussing
must be done very carefully, and if necessary the lens should be
stopped down. There is no need to cover in the space between
the lens and the negative, if the card which surrounds the latter
is large enough to prevent strong light from shining into the lens.
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