This section is from the American Hand Book of the Daguerreotype, by Samuel D. Humphrey. Published S. D. Humphrey, 37 Lispenard Street 1858.
The time of exposure necessary to produce an image upon the Daguerreotype plate, can only be determined by experiment, and requires a liberality of judgment to be exercised on the part of the operator. The constant variation of the light renders it impossible to lay down any exact rule upon this point. Light is not alone to be considered; the amount of coating exercises a deviating influence, also the subjects to be represented are not equally photogenic, some requiring much longer time of exposure than others. This may be easily observed by exposing the plate at the same time to a plaster bust and a piece of black velvet, the first being a much stronger reflector of light than the latter: the time necessary to produce a well developed image of the velvet being about six times longer than that required to produce an equally defined image of plaster. The manner of judging correctly of the time is by the appearance of impression after it has been developed by the mercurial vapors. Should it present a deep blue or black appearance it is solarized or over-timed. This sometimes is to an extent, that a perfect negative is formed, the white being represented black, and the dark light.
An object requiring the particular care and attention of the operator is the proper focus. It is not unfrequently the complaint of sitters that their hands are represented as being magnified and greatly out of proportion with the general figure. This is the case also with the nose and eyes, but in a less degree. As this cannot be wholly remedied, it is desirous to come as near as possible, and in order to do this, it is necessary to present the figure in such a position as to bring it as nearly as possible upon the same plane by making all parts nearly at equal distance from the lenses. This must be done by the sitter inclining the head and bust formed to a natural, easy position, and placing the hands closely to the body, thus preserving a propel proportion, and giving a lively familiarity to the general impression. It is not an uncommon fault among our less experienced operators to give a front view of the face of nearly every individual, regardless of any particular form, and this is often insisted upon by the sitter,* who seems to think the truth of the picture exists principally in the eyes staring the beholder full in the face.
* I might here picture some curious scenes experienced by our operators Every one is familiar with a certain class of our community whose ideas of the importance of a free and easy position of the body are too closely confined with stays, attention to toilet, tightly fitting dress coats and the like, to admit of being represented as if nature had endowed them with least possible power of flexibility. To such we would suggest the following, to be well learned and retained in the mind while presenting themselves before the Daguerreotype camera:
"The experience of one who has often been Daguerreotyped, is, to let the operator have his own way."
Nothing, in many instances, can be more out of place in a Daguerreotype portrait than this, for let a man with a thin, long, defeated-politician-face, be represented by a directly front view, we have, to all appearances, increased the width of the face to such an extent as to reveal it flat and broad, losing the characteristic point by which it would be the most readily recognized. The method we should adopt in taking the likeness of such an individual as above, would be to turn the face from the camera, so as to present the end of the nose and the prominence of the cheek bone equally distant from the lenses, and then focusing on the corner of the eye towards the nose, we cannot in many cases, fail to produce an image with the lips, chin, hair, eyes and forehead in the minutest possible definition.
It should be the study of every operator to notice the effect of the lights and shades while arranging the sitter, and at the same time be very particular to give ease in the position.
No matter how successful the chemical effect may have been, should the image appear stiff and monument-like, all is lost. "In the masterpiece, grace and elegance must be combined."
I will here use the words of another, which are very true:
"So great is the difference in many faces, when inspected in opposite directions, that one of the two views, however accurately taken, would not communicate the likeness-- it not being, the usually observed characteristic form. When the right view of the head is obtained, it is first necessary to consider the size of the plate it is to be taken on, so as to form an idea of the proportion the head should bear to it. The mind must arrange these points before we commence, or we shall find everything, too large or too small for the happy proportion of the picture, and the conveying of a just notion of the stature. The work will have to be done over, and time sacrificed, if this is not attended to. The adjustment of the head to the size of the plate (as seen from the margin of the mat), is not to be taught: everyone must bring himself, by scrutinizing practice, to mathematical accuracy; for something will be discovered in every face which can be surmounted only by experience.
"The eye nearest the camera, in a three-quarter-face, is placed in the middle of the breadth of the plate; the chin, in a person of middle stature, in the middle of the length, and higher according to the proportional height of the person."
In regard to the proper elevation of the camera, it may be here stated that I have found it best in taking portraits where the hands are introduced, to place the camera at about equal height with the eyes of the sitter, in order to bring the face and hands equi-distant from the tube. It will be found, if the above be followed, that by attaching a string to the camera tube, and making a semi-circle, that the face and hands of the sitter will occupy a corresponding distance, and the consequence is that the impression will appear without the hands being magnified. It has been found that a person with a freckly face can have as fine, fair, and clear an impression as the most perfect complexion; this may be done by the subject rubbing the face until it is very red. The effect is to lessen the contrast, by giving the freckles and skin the same color and the photogenic intensity of the red and yellow being nearly the same, an impression can be produced perfectly clear.
When a child is to be taken, and there are doubts of its keeping still, the operation may be accelerated by placing it nearer the window bringing the screen nearer, and placing a white muslin cloth over the head; this will enable you to work in one third of the usual time. Should the person move, or the plate become exposed to the light, it may be restored to its original sensitiveness by placing it over the quick, one or two seconds.