A peculiar trouble which sometimes occurs when developing in the Tank is the appearance of minute semi-transparent spots covering the entire surface of the negative. This is very noticeable on light backgrounds. Photographers have frequently offered the explanation that this is a moldy effect, due to plates being old or having been kept in a damp place. Sometimes the Tank is blamed and is suspected of not being thoroughly clean or that the metal of which the Tank is constructed has an injurious action on the developer.

These explanations are, however, incorrect. The effect is due to minute air bells from effervescence in the water when same is highly aerated. This trouble is most often experienced in the winter and in the early spring. When the water drawn from the supply pipes is highly charged with air, an effervescence occurs which requires some little time to subside.

To prove that this effervescence does occur as stated it is only necessary to draw water into a glass pitcher, tumbler or bottle, and allow it to stand for a few minutes. When the water coming from the faucet is highly charged with air there will be thousands of small air bells form on the inside of the glass. This is just what occurs under the same conditions when developing in the Tank. The air, as it is being expelled from the water, forms numerous small bubbles, which adhere to the plate just the same as to the inside of the glass container. Naturally the bubbles would retard development, but after the development begins, these air bells gradually subside and by the time they have entirely disappeared the action of the developer becomes uniform. The negative will, however, have a spotted or mottled appearance on account of development having been partially retarded where these little bells of air have attached themselves to the emulsion.

This explanation is very simple, the action being of a mechanical nature instead of chemical as might hastily be concluded. The development being retarded only while the air bells are adhering to the surface of the plate explains why spots are only semi-transparent.

To overcome this trouble it is advisable to draw off a sufficient quantity of water, allowing it to stand for a while before using to mix the developer. It is also a good plan to reverse the Tank and shake quite energetically after first immersing the plates. This will insure the surface of the plates being wet over thoroughly and prevent bubbles from adhering. This effect is more liable to show itself when developing in the Tank, as with tray development the rocking motion of flowing solutions back and forth, prevents bubbles from forming and adhering to the plates. A little attention to this detail will save much annoyance at times and avoid unnecessary retouching.

December. Our Illustrations

Schaldenbrand Bros., whose work it is our good fortune to use in illustrating this number of Studio Light, have for a number of years been pleasing their patrons with the very high quality of portraits shown in these illustrations.

C. A. and F. W. Schaldenbrand began their photographic, career with Mr. James Arthur of Detroit and after several years of experience with Mr. Arthur, located in Pittsburgh. They are at the present time conducting a very profitable and high-class portrait studio in the fashionable East End district.

Schaldenbrand Bros, attribute much of their success to the quality of the materials they use in their studio. The continued use of Artura and Aristo Platino, Seed Plates and the Eastman Plate Tank has been the important factor in maintaining the high standard of work that has made their business such a success.

Mr. F. W. Schaldenbrand, the operator, is a most enthusiastic exponent of the principles of tank development. It is in the Tank that he produces the wonderful printing quality of his negatives. They are clean and crisp - the delicate details and gradations are all preserved - there is a total absence of fog which has such a deteriorating effect on the half-tones of a negative.

With Seed Plates and Tank Development he gets quality in the negative; with Artura Paper he gets quality in the print. This high standard of quality in working materials combined with courtesy to customers and good business methods is the secret of the Schaldenbrand Bros, success.

The Eastman Plate Tank will give you better quality in the negative, which means better quality in the finished print.

From An Artura Iris Print By Schaldenbrand Bros. Pittsburgh, Pa.

From An Artura Iris Print By Schaldenbrand Bros. Pittsburgh, Pa.