A Manual of the Collodion Photographic Process - Exposure of the Prepared Plate to the Action of Light
Contents
Part 1
Part 2
- Preparation of Collodion Film
- Immersion of Plate in the Bath
- Exposure of the Prepared Plate to the Action of Light
- Development of the Image
- Fixing of the Image
PART III
- The Whitening Process
- The Camera
- Description of the Camera
- Glass Bath
- Photographic Lens
- Summary of Precautions
- Conclusion
EXPOSURE OF THE PREPARED PLATE TO
THE ACTION OF LIGHT
The third division in the process consists in submitting the sensitive film immediately it is removed from the bath to the camera action. It will be a saving of time if, whilst the plate is in the bath, the focus and the adjustment of the sitter (if a portrait is to be taken) are attended to, for it is necessary, as I have just said, that the prepared plate should be submit- ted to the light directly it is taken from the silver bath, as its sensibility diminishes rapidly.
The length of time necessary to expose the plate in the camera, it is obvious must depend both upon the power of the lens and the intensity of the reflected image; and as the time may vary from one moment to a quarter of an hour, it would be useless to give any precise directions; the operator’s own experience, after a time, will be his best guide. If a positive image is required, less exposure In the camera is necessary; on the other hand, a negative, to print from, will require longer exposure, as considerably more body in the resulting deposit must be accumulated, for it is by means of the varying thickness and density of the shades the requisite effect in the after. printing is produced.
It should be decided before exposing the plate in the camera, whether a positive or negative drawing is desired, in order to vary the time of exposure accordingly.