The modifying operation may be done at once, where the exposure has been long enough to admit it, but generally, and especially when it has been such as to admit of the best result, the image is too soft, too easily washed off to make it safe. But after having been dried and again moistened by immersion in water, the desired modification may be made with safety.
The moistened print is now placed on a sheet of glass, the lower end of which rests on the bottom of the developing tray, and supported by the left hand at a suitable angle; or, better still, in some other way so as to leave both hands free. In this position, and with water at various temperatures, camel’s-hair brushes of various sizes, and a rubber syringe, it is possible to do practically anything.
Tables And Scales:
Comparative Exposures of Various Subjects.—
| Seconds | |
|---|---|
| Open panorama, with fields and trees | 1 |
| Snow, ice, marine views | 1 |
| Panorama, with houses, etc. | 2 |
| Banks of rivers | 3 |
| Groups and portraits in open air (diffused light) | 6 |
| Underneath open trees | 6 |
| Groups under cover | 10 |
| Beneath dense trees | 10 |
| Ravines, excavations | 10 |
| Portraits in light interiors | 10 |
| Portraits taken 4 feet from a window, indoors, diffused light | 30 |
{548}
Table Showing Displacement On Ground Glass Of Objects In Motion
| Miles per Hour. | Feet per Second. | Distance on Ground Glass in inches, with Object 30 Feet away. | Same with Object 60 Feet away. | Same with Object 120 Feet away. |
|---|---|---|---|---|
| 1 | 1 1/2 | .29 | .15 | .073 |
| 2 | 3 | .59 | .29 | .147 |
| 3 | 4 1/2 | .88 | .41 | .220 |
| 4 | 6 | 1.17 | .59 | .293 |
| 5 | 7 1/2 | 1.47 | .73 | .367 |
| 6 | 9 | 1.76 | .88 | .440 |
| 7 | 10 1/2 | 2.05 | 1.03 | .513 |
| 8 | 12 | 2.35 | 1.17 | .587 |
| 9 | 13 | 2.64 | 1.32 | .660 |
| 10 | 14 1/2 | 2.93 | 1.47 | .733 |
| 11 | 16 | 3.23 | 1.61 | .807 |
| 12 | 17 1/2 | 3.52 | 1.76 | .880 |
| 13 | 19 | 3.81 | 1.91 | .953 |
| 14 | 20 1/2 | 4.11 | 2.05 | 1.027 |
| 15 | 22 | 4.40 | 2.20 | 1.100 |
| 20 | 29 | 5.87 | 2.93 | 1.467 |
| 25 | 37 | 7.33 | 3.67 | 1.833 |
| 30 | 44 | 8.80 | 4.40 | 2.200 |
| 35 | 51 | 10.27 | 5.13 | 2.567 |
| 40 | 59 | 11.73 | 5.97 | 2.933 |
W. D. Kilbey, in the American Annual of Photography, gives still another table for the exposure that should be given to objects in motion.
According to his method the table is made out for a distance from the camera 100 times that of the focus of the lens; that is, for a 6-inch focus lens at 50 feet, a 7-inch at 58 feet, an 8-inch at 67 feet, a 9-inch at 75 feet, or a 12-inch at 100 feet.