BIRCH AND BRACKEN.
W. THOMAS.
The choice of subject is only bounded by the limits of exposure, speed of plate and actinic action of light available. The first has already been touched upon, when the lens, and shutter, were dealt with.
Plates have recently been so increased in speed, that it becomes necessary to somewhat modify advice, which a year or two ago, might have been perfectly correct, viz., to work with the fastest plate procurable. But there is this advantage now, as then, that if some convenient form of actinometer be used to test the light, we are able to judge at once, what speed of plate will be necessary to deal with each subject as it arises. There are several forms available, amongst which, the one introduced by Watkins, made so that it becomes a permanent part of the camera, answers remarkably well, especially as it cannot be left at home, without being noticed. In developing shutter-exposed plates, if full exposure has been obtained, then the ordinary modes of procedure suffice, so also when over-exposure occurs, but by far the greater proportion of failures one sees in this class of work, arise simply from under-exposure. There seems so much charm in driving a shutter at its highest speed, and at the same time using the lens stopped down, to secure sharp definition, the wonder is, not that failures flourish, but that any good work is done at all.
With regard to particular developers there is only this to be said. Whatever agent be employed, so arrange that before density is obtained, all the detail you require is first brought out; this simply means, if pyro is being used, it is kept low, until the plate is ready to be treated for density, then a further addition of pyro and bromide will generally suffice to rapidly finish off the work.
When a batch of exposed plates is being dealt with, a most certain method of negative making, will be found in employing in one dish, either one or other of the following one-solution developers:—
No. 1 Formula. | ||
| Amidol | 20 | grains |
| Sodium sulphite | ½ | oz. |
| Water | 7 | " |
No. 2 Formula. | ||
| Dissolve in water | 20 | oz. |
| Metol | 75 | grains |
| then add | ||
| Sodium sulphite | 1¾ | oz. |
| Carbonate of soda (crystals) | 1¾ | " |
| Bromide of potassium | 6 | grains |
No. 3 Formula. | ||
| Sodium sulphite | 1¼ | oz. |
| Carbonate of potassium | ½ | " |
| Eikonogen | ¼ | " |
| Boiling water | 12 | " |
Any of the above developers will be found to rapidly bring out all there is in the plate, and if over-exposure is feared, they may all with advantage be diluted, with an equal quantity of water, in order to slow down their action.