Page 127 - The Wellington photographic handbook

as more and more of No. 3 is used. The exposure has to be increased
at the same time, and the development takes longer. For decidedly-
warm tones the exposure may be as much as six times the normal
and the quantity of No. 3 increased to ninety minims or drops.
Development in this case will take five or six minutes. The warmer
the tone of the finished slide the lighter will be the colour of the
image as it lies in the dish, and this may prove very deceptive.
It is best, therefore, to get into the habit of timing the development
to prevent under or over-developing. Haphazard additions of
bromide should not be made, and if anything like a fair proportion
of the slides is to be successful, the photographer must make up
his mind what tone he likes, mix his developer accordingly and
stick to that developer until he is thoroughly familiar with it,
making his exposures to suit that particular developer and no other.
PYRO AND AMMONIUM CARBONATE DEVELOPER
FOR RICH SEPIA TONES*
The following developer, with WELLINGTON Lantern Plates
that have received from four to five times the normal exposure will
give rich sepia tones, development taking two-and-a-half minutes.
A.
Pyrogallic Acid ... ... 1 ounce 27 grammes
Sodium Sulphite (cryst.) ... 4 ounces 100
Water to ... ... ... 20 ounces 500 c.c.
B.
Ammonium Carbonate . . . 480 grains 30 grammes
Potassium Hydrate ... ... 360 ,, 22 ,,
Potassium Bromide ... ... 240 ., 15
Water to ... ... ... 10 ounces 250 c.c.
One dram each of A and B are taken, and water is added to make one
ounce (4 c.c. of each, to make 30 c.c. in all).
THE WELLINGTON S.C.P. LANTERN PLATES.
Most of the foregoing remarks apply equally to the S.C.P.
Lantern Plates, except that with them no dark-room is necessary
and all operations can be carried out in a room illuminated by
ordinary artificial light. Care should be taken not to expose the
plate to strong direct light, but at about 8 feet from the illuminant,
or screened from its direct rays, the plate can be handled with
perfect safety.
* Before making up any formula, read the notes on pages 125, 126 and 134.
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