Developers that give a brown deposit, or that stain the film will require shorter development than those of the newer developing agents that give a cold black colour to the negative; another fact to be borne in mind is that the image formed by these latter appears to lose more density in fixing than when pyrogallic acid is used.
A perfect portrait negative should have no clear glass shadows, and no part should be so dense as to give white in the finished print, and some negatives which give the best results may have a decided veiled appearance in the shadows.
The temperature of the developer is another important point; in very cold weather the developer should be kept warm, or if in concentrated solutions may be diluted with warm water. In cases of known under-exposure the developer may be used quite hot with advantage. A convincing experiment can be made by cutting an exposed plate in two and developing one half with icy cold developer and the other half with warm. The difference is really remarkable. If the developer has been used hot enough to make the gelatine of the plate feel "slimy" an alum bath is necessary, unless the fixing bath contains chrome alum.
| Metol. | ||||
1. | ||||
| Water | 100 | parts or | 10 | ozs. |
| Metol | 1 | part or | 50 | grains |
| Sodium sulphite | 10 | parts or | 1 | oz. |
2. | ||||
| Water | 100 | parts or | 10 | ozs. |
| Potassium carbonate | 10 | parts or | 1 | oz. |
3. | ||||
| Potassium bromide | 1 | part or | 1 | oz. |
| Water | 10 | parts or | 10 | ozs. |
For normal exposures take 3 parts No. 1 and 1 part No. 2; to each ounce of mixed developer add 40 minims of No. 3.
| Pyro and Soda. | ||||
1. | ||||
| Pyro | 1 | oz. | ||
| Water | 70 | ozs. | ||
| Nitric acid | 12 | drops | ||
2. | ||||
| Sodium sulphite | 10 | ozs. | ||
| Sodium carbonate (pure) | 8 | ozs. | ||
| Water | 70 | ozs. | ||
Equal parts of each, for soft negatives dilute with water. To restrain for over-exposure use potassium, not ammonium bromide. Unless an acid fixing bath is used the negatives are rather green in colour.
| Rodinal and Hydrokinone. | ||||
A. | ||||
| Sodium sulphite | 1 | oz. | ||
| Water | 20 | ozs. | ||
| Citric acid | 1 | crystal | ||
| Potassium bromide | 1 | dram | ||
| Hydrokinone | 2 | drams | ||
B. | ||||
| Potassium carbonate | 2 | ozs. | ||
| Water | 20 | ozs. | ||
| Rodinal | 1 | fluid oz. | ||
Use 1 part A, 1 part B, and 1 part of water.
The question of retouching is a difficult one. There is no doubt that a certain amount of it is necessary on nearly all portrait negatives and even on those of children. But it is equally certain that the great majority of portrait negatives are over-retouched, so much so that their value both as portraits and pictures is nearly destroyed. Yet a certain amount is necessary even for pictorial effect, and perhaps still more when the question of likeness is considered. For as a rule the untouched negative is no more a true likeness than the over-retouched one. The truth lies somewhere between the two. Even if isochromatic plates are used the little differences of colour in the face, and the incipient wrinkles are exaggerated in an unpleasant way. Under-exposed negatives will show these defects in a very marked manner, full exposure will greatly reduce them. Large heavy patches of shadow may be lightened by coating the back of the negative with matt varnish, and when it is quite hard "hatching" upon it with a soft lead. Harsh lights may be reduced by scraping away the matt varnish with the point of a knife. In some cases the matt varnish may be stained with a little aurine or uranine. Exaggerated lines and small shadows must be worked upon from the front and a retouching desk is necessary. The film of the negative will not take the pencil without some preparation. The best surface is obtained by spreading a little retouching medium with the tip of the finger on the part to be touched. A thin film of soft resin is left upon the plate which takes pencil marks readily. A hard lead, No. 4 Faber or Hardtmuth, should be used. The loose leads used in what are called the "ever-pointed holders" are most convenient. The point must be very long and fine, like a large darning needle, and is best made by rubbing the lead on a piece of fine glass-paper. The pencil must be held very lightly and the lines touched away with short light strokes, a heavy stroke only rubs the medium up.