Thin Film
from Dominque Francois Arago: Report, July 3, 1839:
Daguerreotype calls for no manipulation which anyone cannot perform. It presumes no knowledge of the art of drawing and demands no special dexterity. When, step by step, a few simple prescribed rules are followed, there is no one who cannot succeed as certainly and as well as can M. Daguerre himself.
The rapidity of the method has probably astonished the public more than anything else. In fact, scarcely ten or twelve minutes are for photographing a monument, a section of town, or a scene, even in dull winter weather.
In summer sunlight the time of exposure can be reduced to half. In the southern climate two to three minutes will certainly be sufficient. We must note, however, that the ten to twelve minutes in the winter, the five to six minutes in summer, and the two to three minutes in the South express only the actual time during which the sensitive plate receives the image projected by the lens.
To this time must be added the time occupied by the unpacking and mounting of the camera obscura, preparing the plate, and the short time necessary for protecting the plate from the action of light after the exposure. For these manipulations perhaps a half to three quarters of an hour may be required.
Thos who fondly imagine when about to start on a journey that they will employ every moment when the coach is climbing slowly uphill in taking the scenes, will be therefore disappointed in their expectations. No less will be the disappointment of those who, astonished by the success obtained by copying the pages and illustrations of the most ancient works, would dream of the photographic images for reproduction and multiplication of the daguerreotype by means of the lithographic print.
Not alone in the moral world has every quality its defects; this principle applies also to the Arts. The perfection, delicacy, and harmony of the picture images are the result of the perfect smoothness and incalculable thinness of the coating on which M. Daguerre operates. If such a picture is rubbed or even lightly touched, or subjected to the pressure of a roller, it is destroyed past redemption; but, who could imagine anyone pulling apart a fine piece of lace or brushing the wings of a butterfly?
Also see Daguerreotypemania, December, 1839
