Page 128 - The Wellington photographic handbook

The following developer is recommended : —
METOL-HYDROKINONE DEVELOPER.*
Metol 20 grains 1 gramme
Hydrokinone 60 ,, 3 grammes
Sodium Sulphite (cryst.) ... 700 ,, 35
Sodium Carbonate (cryst.) ... 700 ,, 35 „
Potassium Bromide ... ... 6 ,, 0*3 ,,
Water to ... ... ... 20 ounces 500 c.c.
Dissolve in the order given allowing each ingredient to be completely
dissolved before adding the next.
N.B.—All metol-hydrokinone developers should be used at a temperature
of from 60° to 65° Fahr. Below 60° Fahr. hydrokinone rapidly loses its
developing power and at very low temperatures becomes practically inert.
With the above developer and a negative of average density
the exposure at a distance of 6 inches from a 16-c.p. electric light
will be about one minute. If magnesium ribbon is used, \ inch
at about 18 inches from the negative will be found approximately
correct. The tone obtained will be a particularly fine cool black.
Development will take about 30 seconds.
Used in the above manner the S.C.P. Lantern Plate will be
found particularly suitable for weak negatives, from which brilliant
slides will be obtained without difficulty.
By increasing the normal exposure by about one-third, and
adding potassium bromide to the developer very beautiful warm
black and cool brown tones can be secured. Two grains (20 drops
of a 10% solution) of potassium bromide to each ounce of developer
will be found the best average proportion, but the quantity may
be increased up to 20 grains if desired. Development with the
addition of 2 grains of potassium bromide to the ounce will take
about two minutes, the appearance of the slide as it lies in the
dish being a reliable indication as to what its final density will be.
For decidedly warm tones the exposure must be considerably
increased and the following Restrainer added in the proportions
indicated.
RESTRAINER.*
Ammonium Carbonate ... 1 ounce 1 0 grammes
Ammonium Bromide ... ... 1 ,, 10
Water to ... ... ... 10 ounces 100 c.c.
* Before making up any formula, read the notes on pages 125, 126 and 134.
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