The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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Development and Developers
If the image comes up slowly under the dilute developer as first used, and normal exposure is indicated, the dilute developer must be poured off and normal developer substituted ; although, as in the case of pyro, a long-continued action of the dilute developer will give a result very similar to that of the shorter action of a stronger developer, excepting that the weak developer will tend towards vigour and density.
If the dilute developer brings up little or nothing, so that under-exposure is indicated, the following is the course to follow, the quantities being for a quarter-plate : -
Normal developer        ...        ...        ...        ... I\ ozs.
Liquid ammonia          ...        ...        ...        ... I drop.
Potassium bromide ... ... ... ,.. I gr.
Use this till the smell of ammonia disappears; pour off, add I drop more of ammonia, and continue the development, adding more ammonia step by step as the smell disappears. Towards the end of the development, and when it will do no harm to slightly tinge the transparent parts of the negative, the ammonia may be doubled, or even three-folded.
Synthol Two-Solution Developer with Soda.
A. Water ... ... ...        ... ... ... io ozs.
Metabisulphite of soda           ... ... ... 360 grs.
Synthol ... ... ... ... ... ... 60 ..
B. Water ... ... ... ... ... ... 10 ozs.
Soda (washing crystals)        ...        ... ... I oz.
For use, take equal parts of A and B.
Gelatino-Chloride Plates. - Instructions for Use. Exposure. These plates are chiefly intended for contact printing under a negative in an ordinary pressure frame ; when used in this way thay are extremely sensitive to daylight, the time of exposure varying from 1 second to 15 or 20 seconds, accord-ing to the power of the light and the density of the negative. Full exposure in a dull light usually gives the best results. With thin or weak negatives it is better to cover the printing frame during exposure with a sheet of opal glass or white tissue paper, giving sufficient exposure to compensate for
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