Page 105 - The Wellington photographic handbook

EXAMPLE.— It is known that on a certain occasion when the
meter slip took 15 seconds to darken a negative required 40 seconds'
exposure. It is desired to make another enlargement from the same
negative and it is now found that the meter slip takes 12 seconds
to darken. To find the exposure required multiply 40 by 12 and
divide by 15. The answer is 32, i.e., the number of seconds'
exposure necessary.
The fixed focus enlarger is a very simple form of apparatus,
but much good work can be done with it. Its disadvantages are
that the worker is limited to a particular size of enlargement, and
that he has but few facilities for controlling his results by shading
portions of the picture during printing.
The greatest number of enlargements, however, are made by
means of an enlarging lantern.
ENLARGING WITH A LANTERN.
An enlarging lantern is simply a magic lantern, in which special
care has been taken to prevent light leaking out into the room in
which it is being used. The negative is put into the position
occupied by the slide, and this having been sharply focussed on
the easel, the lens is capped with the red glass cap, and a piece
of WELLINGTON Bromide, B.B., or S.C.P. is pinned on the
board and the exposure made.

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