An under-exposed negative which contains no strong contrasts, may be developed very fully without harm ensuing, if only fog, whether due to the developer or the light of the dark-room lamp, is avoided, but in all cases it is safer to develop lightly and trust to intensification for improvement. Such a negative, if strong contrasts are present, will show the details in the high-lights clearly, G but the shadows and half-tones will be uniformly grey. The object must be to strengthen the half-tone and shadow as much as possible while adding as little as may be to the lights. There are many intensifiers which will do this, but the simplest is the uranium inten-sifier, which has the further advantage that those who are skilful in the use of the brush may remove it entirely from the high-lights. The following solution is to be made up-
In this the negative is immersed till the surface becomes a warm brown colour. If the action is carried too far, the whole of the image will change to a brick-red colour, and the effect will be to accentuate the contrasts. If, however, the action is checked before the half-tones and lights are completely affected, the greatest possible addition will have been made to the strength of the shadow detail, and whilst fair printing density will have been attained, the contrasts will not have been increased. The negative should then be rinsed in water, slightly acidulated with acetic acid, till the yellow colour in the unexposed margins is discharged. Prolonged washing will result in the whole or the greater part of the intensification being removed. If, when the negative is dry, it is found that the contrasts are still too strong the intensification may be removed from the high-lights by the application to these parts of a 1 in 20 solution of ammonia by a camel-hair brush. The surplus liquid should at once be taken up with a bit of blotting paper to prevent it from spreading to parts where it is not required.
Many other intensifiers and reducers can be employed, but the object has been to avoid confusion by giving one only for each purpose and to select those which are simple in their application. Most of the chemicals are of a poisonous nature and can only be sold by a chemist to whom the purchaser is personally known, and in consequence cannot be obtained from the ordinary photographic dealer. Much may be done by the pencil and stump to improve the quality of faulty negatives, high-lights may be rubbed down with methylated spirit applied with a piece of chamois leather, and for the same purpose, Basket's reducer, made by mixing globe polish, olive oil and terebene may be employed in a similar way. Papier minera may also be stretched while damp over the back of the negative, and when dry the portions over the high-lights may be cut away with a sharp knife. All these methods, however, are somewhat outside the scope of the present article.
In conclusion, one word of advice is offered. All negatives, and especially those which have to receive chemical treatment, should be thoroughly fixed and thoroughly washed. The latter point is so frequently referred to that its value may be supposed to be well understood, but thorough fixation is of even greater importance and when the photographer has reason to suppose that intensification or reduction may be necessary, he will do well to employ two fixing baths, allowing the negative to remain the same time in each, which he is accustomed in the ordinary way to give to the single bath.
Taken with the Sinclair "Una" Camera held in the hand.
J. A. Sinclair