A Manual of the Collodion Photographic Process - Immersion in the Bath


Contents

Part 1

Part 2

PART III


Immersion in the Bath

The second division —The plate of glass prepared as above, and partially dried, is next submitted to the action of the nitrate of silver bath of the following strength:

  • Crystalized nitrite of silver............... 30 grs.
  • Water................................................ 1 oz.


This is an operation of much nicety, and requires a steady hand and some little care. The plate is held firmly in the hand, and plunged at one motion into the bath; otherwise, if any halt is allowed, a line will be produced across the plate, however short a time the stoppage may be.


It should remain in the bath about one minute, for the double purpose of saturating the film with iodide of silver and removing the oily or streaky appearance from its surface; which latter effect would, if allowed to remain, cause an unequal sensibility in the coating, and consequently an unequal development of the image, which nothing can afterwards efface.


In my own practice of the process, I generally find it more convenient and cleanly to use a glass bath, so contrived as to allow the light to act upon the prepared plate whilst in it, and during. the saturation of the film; consequently the two operations are conducted at the same time. The prepared glass, therefore, need not be removed from the bath until the light has performed its part, and the development of the image can be proceeded with.


The contrivance for this purpose with the glass bath is very simple, as it merely requires that the inside of the front glass of the bath should be adjusted to the same plane in obtaining the focus as the ground glass screen.

Thus, as I have said above, the saturation of the film and the action of light are going on at the same time. This plan, particularly with large plates, ensures more certainty in the operations. There is also less liability of the film becoming stained or injured by contact with the sides of the frame into which it is placed in the camera.

It is possible, however, that this plan, although it offers many advantages, cannot be made available, from the difficulty of procuring the kind of bath it requires. I shall, therefore, defer any farther remarks on this point until I come to speak of the Camera, and proceed with the manipulation, employing the old plan of placing the plate after removal from the bath into the previously adjusted frame of the camera.