t
4
The instrument has been light-proofed very carefully, fin orange
filter can be swung in below the lens during orientation of the
light-sensitive sheet on the projection table prior to exposure,
thus eliminating any risk of fogging.
Flattening the photo paper before exposure calls for some care in
order to avoid local blurring and image distortions. Although the
met process provided complete flatness, it is not preferred by many
users. Conseguently, a suction table with 106cm x 106cm working
surface has been developed for the E4. The coating is of re
sistant white plastic and is provided with more than a thousand
small holes which lead to the suction channels. A selector knob
allows for the choice of one of three different suction-area sizes,
thus providing for efficient flattening with sheets of various
sizes. The suction is improved by laying the magnet strips along
the sheet edges.
The electromagnetic dual-lamella shutter of the Reprogon can be
operated either by a switch or through the electric exposure timer. f
When the shutter is opened by means of the switch, the aperture is
set automatically at f/5.6, thus providing full illumination when
preparing for rectification. When the shutter is closed before ex
posing by using the exposure timer, the aperture automatically is
reset at f/8.
The negative stage of the E4 is equipped for roll film, cut film or
glass plates of various formats, and is light-proof on all sides
even when roll film is used. Coincidence crosses for exact centering
of the negatives are provided on the exchangeable negative carriers.
In designing the instrument, every effort was made to provide
a practical and convenient arrangement of the operational controls,
so as to make the work easy with safelight illumination, and so
that the settings can be made from one position. The switches and
setting controls are therefore all located at the front edge of the
projection table. All switches and scales are illuminated by red
light and are easy to see and read even in poor darkroom lighting.