This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
594. A very mistaken idea seems to prevail among a large class of workers, that retouching applies only to portrait negatives. It is a fact that there are very few negatives produced that could not be improved in one way or another, if ever so slightly, by a certain amount of penciling or etching as well as other hand work. Little defects are bound to present themselves, which, if left in the negative, may entirely ruin what would otherwise be a very pictorial effect. Then again, there are many subjects which could be greatly improved if one only knew the manner in which to make the necessary alterations.
Landscape Subjects. The chief defects in landscape negatives, from the standpoint of the artist, are halation; too much or too little intensity; over-strong highlights or shadows; lack of clouds through over-exposure of sky; blurred figures and trees; light streaks from faulty plate-holders; undesirable loss of detail through hazy spots; imperfect lighting of subjects; lack of definition at the edges, due to imperfect covering of the plate by the lens used, etc. All of these defects may be remedied more or less by proper treatment.
596. There are various ways of accomplishing the desired result, but the manner of proceeding to work upon the negative to make the necessary alterations is practically the same as that for the retouching of the portrait negatives. Etching receives first consideration, and then the reducing paste is applied where necessary, the paste, of
course, always being used after a certain portion has been etched, in order to smooth up the raggedness that might have been caused by the use of the knife. The application of the lead to the mediumed film is the last step, with the exception that at times it will be found necessary to use what is known as "splatter" work on the glass side of the negative.
Architectural Subjects. The alterations necessary in negatives of buildings and various architectural subjects are somewhat different than those required in landscape and other exterior work. There are two distinct reasons for photographing an architectural subject, the first being to produce a technical record of the subject, which necessitates obtaining minute detail in every feature; the second, being simply to secure artistic interpretation of the subject.
598. The greater portion of the necessary hand-work on architectural negatives is the straightening and strengthening of lines, accentuating of high-lights and shadows, and the removing of any defects which might have occurred during the process of manipulation, such as pin-holes, air-bells, light fog, etc.
Etching. In landscape work the knife will be chiefly required to remove specks, high-lights on leaves, and for sharpening moved figures. Where figures or objects have moved, the double outline in the denser portion? must be cut away and such shadow detail as may have been marred by the movement put in with light touches.
600. The negative should always be carefully studied before attempting work on it. First decide what obnoxious patches of light should be removed or subdued in the lights and shadows. Both the etching knife and the reducing paste will come into play here. The latter is very essential where large patches of light are to be reduced, as, especially for the beginner, an even reduction is much more easy to secure with the reducing paste than by employing the etching knife, for it requires much more practice with the knife, to become skillful, than with the reducing paste.
You should, however, practice as much as possible with the use of the knife, for it is by practice only that you will master it.
601. The Schriever Reducing Paste is a most excellent medium to employ for this purpose. It is possible, however, to use the mixture given in Chapter XXIII (Lesson Xv. Reducing Paste) (Child Photography), paragraph 370. There are times when portions of the negative may be reduced by the application of pumice-stone or rotten-stone (the latter being of a much finer grain), a piece of cotton being dipped in absolute alcohol (not methylated) and this, in turn, in a little of the powdered stone. This mixture should be evenly applied by friction to only that portion of the negative that you desire to reduce. When the density has been cut down to the required depth you can wipe the powdered stone from the negative with alcohol, and then if the appearance is satisfactory, proceed to work on the patch of light which you wish to subdue.