This section is from the book "Modern Photography In Theory And Practice", by By Henry G. Abbott. Also available from Amazon: Modern photography in theory and practice: A hand book for the amateur.
Retouching is seldom practiced by amateur photographers and as a rule when they have work of this class they usually give it out to the professional. In fact, retouching is an art in itself and it is not every professional who can do it properly. To be a good retoucher you must be something more than a good photographer, you must be an artist. It is the act by which, as a rule, the photographer flatters his patron. By its means he removes the wrinkles, freckles, crows' feet, moles and other distinguishing marks but at the same time unfortunately destroys the likeness. Retouching is almost wholly applied to portraits, although now and then a marine or landscape negative may be improved in some of its details by judicious retouching. It is an art which can only be acquired by assiduous practice and no amount of cut and dried rules will make a first class retoucher. When working on portraits great care must be exercised not to overdo it or the result will be a failure so far as the likeness is concerned. In portraits of elderly people the retouching should be confined to the shadows on the face and no attempt should be made to remove the wrinkles and crows' feet at the corners of the eyes.
The first requisite is a retouching stand of some kind. This can be purchased from a photographic supply house or the amateur can make one himself if he is at all ingenious and handy with tools. Fig. 29 illustrates a home-made retouching stand which is very easily made. It consists of three small, cheap frames. Two of these frames are hinged together at the front and the third, which is smaller than the others, is pivoted to the horizontal one, The smaller frame holds a mirror, or a piece of white cardboard will do. The horizontal frame has four feet to raise it from the table to give room for the mirror to swing. The other large frame is placed at an angle of about 450 but the angle may be varied by means of the adjustable foot at the side. In this upper frame is placed a piece of ground glass on which the negative lies. A piece of plain glass could be used instead of ground glass and it could be covered on the back with matt varnish. Just below the negative is a flat wooden support which holds the negative in position and the support may be raised or lowered according to the size or part of the negative that is being worked upon. This adjustment is made easy by boring a number of small holes in each side of the front and holding the support in position by means of wooden pins which fit in these holes. Attached to the upper frame is still another one, made of heavy wire and pivoted, so it can be raised or lowered. This wire frame acts as a support for the focusing cloth or a piece of black cambric which shuts out all light except that which comes in through the ground glass.
The stand being ready, the film side of the negative is lightly rubbed with retouching varnish as explained when spotting out. When the varnish is dry the plate is placed on the ground glass with the film side out and the support adjusted so the negative is about central. Two or three hard pencils should be purchased, preferably H, HH and Hhh. These should be sharpened to a long taper point and the final point should be put on them by means of a piece of fine emery paper. The emery paper should be glued to a small piece of board and kept on the table close to the retouching stand, for the points of the pencils must be kept needle sharp and constant application to the emery paper must be made. In sharpening, keep the pencil turning in the fingers and the fine point is easily secured Take a piece of black paper, such as plates are packed in in their boxes and trimming it to the size of your negative or a little larger, cut a round hole in it near the center and about three-quarters of an inch in diameter. Place the screen over your negative so the circular hole will come over that portion which you are about to retouch. This screen has two uses, one to cut off all light except at the point at which you wish to work and the other to keep the ringers and hand from coming in contact with the film. The latter is quite necessary, particularly in summer when the hands are liable to perspire. The angle of the mirror or the frame may be shifted so as to throw the light directly on the ground glass. Retouching may be done at night by means of artificial light by placing the stand so that the mirror will reflect the light. If done in the daytime the operator should face a window, a north light being preferable. A strong reading glass will be of great assistance in retouching, as the lines and dots should be very fine and the work is very fatiguing on the eyes.
Another very simple retouching stand is shown in Fig. 30 and it can easily be made by any one. Its general shape is that of a truncated pyramid. The top A should be made of tin or zinc and the sides B and C can be made of light wood, tar board or any other suitable material. Four pieces of tar board, joined at the edges by gluing on strips of black muslin, will answer very well. In one side should be cut an opening, say 5 x 8 inches, as shown at B and in the opening should be fitted a piece of ground glass. In the center is placed a small lamp which will illuminate the negative. A small projection should be glued on just under the ground glass, on which to rest the negative.
As we said before, retouching can only be acquired by practice but a few hints may be of value to the amateur who proposes to try his hand on this work. Each retoucher has his favorite method of working. Some use small stipples and commas, others use wavy hair-like lines and others employ both on one negative.
Fig. 31 is an illustration made from a photograph before it was retouched, Fig. 33 was made from a print from the same negative after it was retouched, and Fig. 32 gives a general idea of where the retouching was done. Fig. 32 is only a reproduction of the retouching lines as near as an artist could follow them with pen and ink and in the original of course the lines were much finer and blended into one another. In nearly all instances the retoucher works with the extreme point of the pencil, holding it at right angles to the plate.
This negative was retouched by a professional and you will note that comparatively little retouching has been done, in fact just enough to even up the lighting of the face. In Fig. 31 you will note that a straggling lock of hair has escaped from the hat and the retoucher has removed it, so that it does not show in Fig. 33. These illustrations being made by the half-tone process much of the detail is lost and the difference in the illustrations is not so marked as it is in the photographs. Sometimes the retoucher applies the plumbago by means of the finger tip or with a stump, such as is used in crayon and pastel work. This is only done where larger surfaces require lighting up. It is well for the amateur to work slowly, taking a proof of his negative now and then to see what effect his work has produced. If the retouching shows in the print or is not satisfactory, it can be removed by means of a soft rag dipped in turpentine. Above all, avoid doing too much retouching; soften down the harsh lines usually found on each side of the nose and soften up the dark side of the face (the side that is light in the negative) just enough to bring the two sides in harmony. After the retouching is to your satisfaction, it is well to varnish the negative in order that the retouching shall not become blurred through handling. The varnishing and general care of negatives will be described later on.