A Manual of the Collodion Photographic Process - Description of the Camera
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
Description of the Camera
I will proceed to give a general description of the camera I have constructed, premising that it admits of being made as a very light folding camera, if thought necessary.
It is a wooden box, 18 inches long, 12 inches wide, and 12 inches deep, and is capable of taking a picture 10 inches square. Externally it may be thus described:—In front it has a sliding door, with a circular opening in it, to admit the lens: this sliding door enables the operator to lower, or raise, the lens, and con- Sequently the image formed by it, on the ground glass, as the view may require. The two sides have openings cut in them, into which sleeves of India rubber cloth are fixed, to admit the hands of the operator; and are furnished with India rubber bands at the lower ends, which press against the wrists, and prevent the admission of light.
The back of the camera has a hinged door, fitted at its upper part with an opening of just sufficient size for the eyes, and shaped so as to fit close to the face. A black cloth is tied round this end of the camera, to prevent any ray of light penetrating at this opening. In the top of the camera near the front is inserted a piece of yellow glass, to admit a small quantity of yellow light, and is closed with a hinged door to regulate the quantity of light required.
The interior of the box is furnished with a sliding frame, to support the ground glass or the bath and the prepared plate; and it has a stop, by means of which any focus from 3 inches to 15 inches can easily be obtained.
The bottom of the camera is furnished with a gutta percha tray, about 1 inch deep, to hold the washings, &c., when the camera is in operation.
Also, the bottom of the camera at the back has an opening cut in it, extending nearly the whole width of the camera, and as far in as the edge of the gutta percha tray.
This opening is intended to admit, when the camera is in use, a light wooden case containing the glass bath, focusing frame, stock of glass, — and paper required in the process.
There are various other little contrivances which I have not specified, such as a drawer for the pictures, a shelf for bottles, &c.
This form of camera will admit of the following manipulation. Having placed it upon a stand pointing to the object to be taken, the hinged door at the back is opened, and the bath is three parts filled with the solution of nitrate of silver; a plate of glass is then taken from the cell, and cleaned if necessary.
The collodion is poured on in the manner previously described; when the film has set a little it is immersed in the nitrate of silver bath, and the lid of the bath is closed down upon it. The next step is to obtain the focus with the ground glass: this can be done’ whilst the collodion is becoming iodized.
After adjusting the sliding frame to the proper focal distance, the camera must be closed, and the rest of the process conducted by passing the hands through the sleeves, and placing the eyes close to the aperture in the back of the camera, and drawing the black cloth over the front of the head.
By the aid of the yellow light admitted from the top, the operator can carry on the rest of the process. The plate is now ready for the action of light, and is taken from the bath; or the bath itself, with the plate in it, is placed in the sliding frame. The refracted image is at once thrown upon the sensitive plate. After the requisite exposure, the plate is taken from the bath, and the picture is developed with the solution previously described, The progress of this operation can be seen by aid of the yellow light, keeping the eyes close to the aperture behind.
When, from experience, the picture is suffciently brought out, a little water is poured on the glass to wash off the developing solution, and the drawing is partially fixed by the application of a small quantity of a solution of common salt.
The drawing may now be removed from the camera without fear of being injured by light, and the remainder of the operations can be conducted outside the camera.
If the film is sufficiently strong to bear re- moval from the glass, the following procedure is adopted. The plate of glass is placed hori- zontally upon the back lid of the camera, which is hung so as to form a temporary table, and the film is loosened from the edge of the glass with a flat strip of glass; a sheet of damp paper is then placed flat on the drawing, and rather within its upper edge; the film is turned over the end of the paper, and a glass rod is placed just within the edge. The sheet of paper with the collodion in contact with it is now raised from the glass, and rolled up on the glass rod. When the drawing is entirely en- closed in the paper, the rod is removed, and the delicate film thus encased is put away into its proper receptacle, to be finally fixed and mounted at leisure.
The drawing thus rolled up can be preserved for months without injury, provided it is kept slightly damp; and if. each drawing is enclosed in another sheet of paper, its preservation is still further secured.
The advantages of a camera of this kind may be thus enumerated :
It allows the preparation on the spot of the most sensitive surfaces; their immediate use whilst the sensibility is at its maximum; the ready development of the image, and after fixing.
All these operations being carried on consecutively, the operator can, after the first trial, see what results the progress of his labours is likely to produce.
It gives him the power of shading off any portions of the view during the action of the light, by holding in front of the prepared plate and near the lens a moveable screen, or any flat piece of wood, as the case may require; thereby preventing the too rapid action and consequent solarisation of the distant portions of the scene. The spire of a church, for in- stance, pointing upwards into a bright sky, often requires this precaution to prevent its being entirely lost. Other instances of this effect will readily suggest themselves to those at all acquainted with the art.
The camera can be made, with slight modifi- cations, applicable to any other process on paper or glass, and of course obviates the necessity of any kind of portable tent.