The Dictionary Of Photography

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

Home | About | Photography | Contact






Development and Developers
generally be omitted, and also for rapid shutter exposures, and portrait work in the studio. This developer gives exceedingly fine and delicate negatives, with full detail in the high lights, and of good colour for printing.
Pyro and Soda Developer.
No. i.
Pyrogallic acid ... ... ... ... ... I oz.
Nitric acid        ............... 20 drops.
Water.................. 80 ozs.
No. 2.
Sulphite of soda (crystals) ... ... ... 10 ozs.
Carbonate of soda (crystals) - washing soda 8 ,, Water.................. 80 ..
No.. 3.
Bromide of potassium ...        ... ...        ...        I oz.
Water ... ... ... ... ... ... 9 ozs.
To develop mix equal parts of Nos. 1 and 2, and add 10 minims of No. 3 to each ounce of the mixed developer, or, instead, 3 ozs. of No. 3 may be added to the 80 ozs. of No. 2. For rapid shutter exposures omit the bromide. This developer gives bold vigorous negatives of a neutral grey colour. In either of the foregoing developers, the No. 1 solution may be mixed as a stock solution, if preferred, by using only 8 ozs. of water instead of 80, and diluting to above proportions, as required.
General Notes. Dust the face of the plate just before placing it in the dish for development, and, putting it face upwards, pour the mixed developer steadily over the dry plate, removing any air bubbles by passing a flat camel-hair brush (kept specially for this purpose) over it immediately ; rock the dish gently, taking care to keep the film or plate well covered with the solution. When using pyro developer, where a plate is found to be under-exposed, the normal developer should be at once diluted by the addition of water ; in some cases as much as three or four times its bulk of water may be added with advantage, the development proceeding proportionately slowly. By this means detail is brought out in the shadows without permitting the high lights to gain too much density. Under-exposuie should always be
185