If the image flashes out immediately upon the application of the developer, the paper has been over-exposed. A strong dose (one or two drams) of ten per cent. bromide added to the developer may help to save it, but the enlargement will probably look poor and flat and of bad colour when finished. If the picture appears very slowly, and refuses to gain in strength, under-exposure is the cause, and two or three drams of a ten per cent. solution of sulphite of soda may improve matters, but as a rule the most satisfactory plan will be to make another exposure. With regard to the strength of the developer, that given is very suitable for negatives of normal density, but some papers may require a little more amidol, the appearance of the finished enlargements will guide the reader in regulating the quantity to suit the particular paper with which he may be working. The enlargement should be washed in plenty of running water from the tap to arrest development, and then fixed in:—
| Hyposulphite of soda | 4 | ounces. |
| Water | 20 | " |
A quarter of an hour should be allowed for fixation, but it is better to use two baths, giving ten minutes in each. After washing in running water for a couple of hours they may be hung up by one corner to dry, or pinned down to a blotting board.
Enlargements produced in the manner described should be of a pure engraving black colour, and if they are mounted upon pure boards with freshly made Glenfield starch, they should prove permanent. Enlargements are frequently toned to various shades of brown and red, generally by the employment of the uranium-toning bath. Although the colours so obtained are often very artistic and pleasing, no reliance can be placed upon the permanence of an enlargement so treated, and the writer strongly recommends that when warm coloured prints are desired, an enlarged negative should be made and prints made therefrom in carbon, silver, or sepia platinotype.
ENLARGED NEGATIVES.
The production of an enlarged negative presents no difficulty that need deter any careful worker from attempting the work. No additional apparatus to that already described will be required, and either day or artificial light may be employed. In the first place a transparency must be made from the small original negative. It may be made either by contact or in the camera, preferably the latter as then the acme of sharpness will be obtained. If, however, the reader is acquainted with the carbon process he cannot do better than make a carbon transparency, for such are specially adapted for the production of enlarged negatives. Many, however, will prefer to make the transparency on a bromide plate, and as this is the part of the process which requires the greatest amount of care, and as in fact the quality of the enlarged negative will entirely depend upon the character of the small transparency, it is necessary to deal with the matter somewhat in detail. Preconceived ideas of quality based upon the appearance of a good lantern slide must be put aside, for that is not at all what is required. What is wanted is a transparency in which every possible detail existing in the negative has been reproduced, and which in comparison with a lantern slide would look rather flat and over-exposed. Every possible precaution should be taken to avoid granularity or coarseness of image, therefore a slow plate is almost essential; plates coated with lantern-slide emulsion are now obtainable, and will be found very suitable. A full exposure should be given, and a weak and well-restrained developer employed. These conditions tend to the production of the qualities desired. Warm coloured transparencies so produced generally have a finer grain than those developed to a black or colder colour, but unless the colours produced are fairly uniform, considerable variation in exposure when making the enlarged negatives will be necessary, and for this reason it would perhaps be better for the beginner to aim at the production of good black transparencies possessing the qualities indicated.
The small transparency, having been fixed, washed and dried, should be edged with black paper to prevent any subsequent fogging of the plate, by the lateral spreading action of the light. It is then placed in the enlarging apparatus, just as in the case of a negative, and carefully focussed. This operation must be very carefully performed. The writer uses a thin and very sharp negative of an architectural subject to focus with, afterwards substituting the transparency which is to be enlarged. Landscape subjects, consisting chiefly of foliage, are seldom critically sharp, and it is then difficult to secure a sharply-focussed enlargement. The remainder of the operation is extremely simple. In the place of the ground-glass screen (which in this case should have its rough or ground side nearest to the enlarging lens) a slow dry plate is placed, backed with a piece of cardboard covered with black velvet to avoid reflections and possible fog. The exposure should be full, and a weak developer employed. Trial exposures may be made on quarter-plates, coated from the same batch of emulsion, which the manufacturers will willingly supply, if the purpose for which they are required is made known. Pyro will be found the most suitable developer, but it should contain a full proportion of sulphite, and not be too strong. Exposure and development should be so adjusted that by the time every possible detail has been developed up, the plate will not have become unduly dense. If expense has to be considered, a piece of slow smooth bromide paper may be substituted for the large dry plate in which case the result will be an enlarged paper negative. For large sizes, 15 × 12 and beyond, the latter is a very economical method of working, and the negatives will be found to yield most artistic prints, and if the operations have been carried out as described, and the prescribed conditions carefully observed, the grain of the paper will not show obtrusively or unpleasantly in the prints.
An alternative method of working, and one which admits of a large amount of control over the ultimate result, is to make in the first place a large transparency of the full size that the enlarged negative is desired to be. All the precautions upon which stress has been laid should be observed in regard to the choice of plate, developer, etc.; but in this case the enlarged transparency may be given a little more vigour and sparkle than would be desirable if the other method of reproduction were adopted, though in this the reader must be guided by the particular effect which he may be seeking to produce in his prints. For this purpose pyro will be found to be the most suitable developer, in that it permits of a large amount of control. From the large transparency a negative is produced by contact printing either upon a plate, or upon a piece of bromide paper.
The great advantages of the latter mode of working are the facilities which are afforded for retouching or working upon the large transparency. Negative retouching is always a difficult operation to an amateur, for he cannot see the effect of his work until he has made a print; whereas, in retouching a transparency the effect produced by each stroke of the pencil or brush is at once apparent. In the space at disposal it is not possible to describe the various ways in which improvements can be effected. First there are the chemical aids of local intensification or reduction. Then much may be done by the judicious use of a pencil, but the part to be retouched must first be lightly rubbed with a little retouching medium in order to make the pencil bite. In extreme cases the back of the negative may be covered with tissue paper upon which a stump and chalk may be used at discretion.
The novice must not be disappointed with the appearance of his enlarged negative when it is finished, nor should he form an adverse opinion of its printing qualities until he has made a print from it. Confessedly an enlarged negative generally presents a different appearance to one that has been taken direct, and may even seem to lack some of those qualities that are commonly regarded as essential to perfection, but if the final result, the picture, comes up to our expectations, we may surely dismiss any lingering doubts as to whether the enlarged negative conforms to certain preconceived notions of technique, and it should be enough for us to know (and the fact is incontrovertible) that some of the finest and most artistic photographs ever shown owe their existence to this method of production.