By permission of Jury's Kine. Supplies, Ltd.
The Jury Combined Camera and Printer.
In winding the film upon the frame, and indeed during all the operations, the operator should be careful not to touch the gelatine coating of the ribbon with his fingers. The finger nails should be kept well trimmed so that scratching may be avoided. A touched film is usually marked, for the touch leaves a deposit of grease, which interferes with the action of the developer.
The frame, with the film wound upon it, is lifted off the stand and carefully placed in the developing bath, into which the developing solution has already been poured. If it is inserted gently no air bubbles or bells will form on the emulsion, but if there should be any such they can be removed at once by means of a large, flat, soft, camel hair brush. In order to secure first-class results, the developing solution should be kept at a temperature of 65° Fahr.
The developing solution is rapid in its action and the film must be watched closely. The frame must be kept rocking so that the solution may remain in movement. This enables it to act upon the whole surface of the film equally. Should development take place too quickly—(i.e. the images flash up almost instantly)—the frame should be removed at once from the developer and immersed in the rinsing tray to allow a few drams of the restrainer solution to be poured into, and mixed with, the developer. On the other hand the film may be under-exposed, and then the images will appear very slowly.
Development proceeds exactly as in the case of a glass plate, and the same judgment is required to determine when the process has been carried far enough. When this point has been reached the frame is lifted out of the developer and placed in the rinsing tray to receive a thorough washing. Water is a kind friend in cinematography and should be used ungrudgingly. Three or four thorough flushes will suffice to rinse the film satisfactorily, and then the frame is placed in the fixing bath. This is made up as follows:—
| Avoirdupois. | Metric. | |
| Water | 64 oz. (fluid) | 2,000 c.c. |
| Hyposulphite of soda | 16 " | 480 grammes |
| Sulphite | ¾ " | 22 " |
| When fully dissolved add the following hardener. | ||
| Powdered alum | ½ oz. | 15 grammes |
| Citric acid | ½ " | 15 " |