American Hand Book of the Daguerreotype

by S. D. Humphrey

In the great catalogue of complaints made by operators, none is more common than that alleged against the quality of plates in general use. Although the greatest diversity of opinion exists upon this subject, nevertheless the plates of every manufactory share in this universal condemnation.

To be sure it cannot be denied but that this necessary article of utility in the photographic art has undergone a sad deterioration in quality owing to the increasing demand and great reduction in price—the plates of the present day being by no means so heavily coated with silver as formerly—but the complaint alluded to is not predicated so much upon the thinness of silver as upon a mysterious something which has conferred upon the plates the epithet of not good.

That this complaint is in a great measure groundless appears evident from the fact that while, with the same brand of plates one operator can work successfully, another encounters the greatest difficulty; while one is able to produce beautifully clear and altogether satisfactory results, the other labors under the troublesome annoyance of innumerable specks, large dark insensitive patches and brown map-like portions, together with divers other blemishes, sufficient to prevent him from obtaining anything like a tolerable impression.

From this wide difference in the results of the two operators using identically the same article, it is but reasonable to conclude that the complaint is founded in error; while the inference is no more than just, that the fault may be traced to a want of practical skill on the part of the complaining operator himself; rather than to the inferior quality of the plates.

The question, then, whether the plates are unfit for use, or whether those who pronounce them so understand how to use them, appears to be satisfactorily answered. It therefore becomes a matter worthy of investigation, to ascertain what superior judgment and skill one operator possesses over another which enable him to work successfully a quality of plate, pronounced by the other entirely useless.

Suppose we make a critical examination of one of the repudiated plates. From its external appearance we have little hesitation in pronouncing it to be French; indeed, this presumption is strongly corroborated by the fact that it is ornamented upon one of its corners with a brand to designate the manufactory from which it emanated.

Upon close inspection we cannot fail to notice a striking peculiarity upon the surface; the roughness is very remarkable; the planishing hammer has left amazingly visible indications of its busy work. One would suppose the manufacturer intended the surface of the plate to represent the undulations of the sea, instead of that smooth and level character so strongly recommended by M. Daguerre.

Such a plate necessarily requires at the hand of the operator considerable labor before the surface is in a proper condition to receive a suitable polish from the buffer. The least reflection in the world should teach any one that so long as the undulatory character continues upon the surface of the plate, it is in a very imperfect condition for buffing, because the buffer cannot touch every point equally; the elevated portions alone receiving a high degree of polish while the depressed portion, from their roughness acting as nuclei, gather dust, rouge, and other foreign bodies, so detrimental to sensitiveness. The secret of the superior judgment and skill of one operator over another, is intimately connected with this point: his success depends very much upon the first process of cleaning the plate.

Let us examine the manipulation of the complaining operator. He takes one of these plates and gives it a careful scouring with rotten-stone and alcohol or any other liquid preferred for this part of the operation—that is, he gives it what he terms a careful scouring—very gently indeed because, from the frequent trials he is in the habit of making in the camera, he fears he will rub the silver entirely away before he succeeds in obtaining a good impression. The dark patches, specks, and granular appearance resulting entirely from the unevenness of the surface of the plate, look like copper to him, and he is surprised that he should have rubbed away the silver so soon, particularly by such delicate handling.

The judgment and experience of the successful operator, however, teach him that scouring injures a plate less than buffing. He knows that unless the hammer marks be obliterated, he cannot by the buffer produce a surface of uniform polish and sensitiveness, without which a fair proof is extremely doubtful; he knows that the time employed in the preliminary operation of cleaning the plate properly is economy.