PHOTOGRAPHY.

Taranaki Daily News, Volume XLVII, Issue 8091, 23 April 1906, Page 4

PHOTOGRAPHY.

However unsatisfactory or uncertain intensification is, it is a periectly legitimate process ot negative improvement to which one may have to resort at tiimti. It seems generally admitted, however, that a celluloid tilm does not yield as good results after mercury intensification as does a glass plate, though this probably applies only or chiefly to a mercury intensifies contain-! ing acid and followed by a strong alkali. As has been recently pointed out, when using mercury there should be no hydrochloric acid in its constitution, nor should ammonia be used as the " blackener," owing to the tendency of both these chemicals to frill the film from its base. The most perfeofc washing, to get rid of all traces of hypo used for fixing, must be given if the image is to be intensified. The fixation mu6t be full. If strippiing films are used the intensification ought to be performed before the film is stripped. The use of strong acids, alkalis, or spirit is not recommended with films. The formula for mercury intensiner for films is as follows: Mercurio chloride, loz; ammonium chloride, 4oz; water, 20oz. After thorough bleaching in this solution (which is intensely poisonous) the films are washed for a few minutes, and then transferred to a bath of sodium sulphite, loz; water, 10oz. Directly the image is blackened all over, and through to the back, the films are removed to water, and, after a few minutes' washing, may be pinned up to dry.

There is a fascination about photographing animals, if only on account of the sense of achievement when, after hours of patient endeavour, you succeed in getting an imago of the animal well posed and showing no signs of movement. Even domestic animals—cats and not nearly so easy as one might suppose, that is if we are going to be at all particular as to expression, attitude, etc. Mrs Cadby, who has identified herself almost as much with clever and dainty cat portraits as she bas with the class of decorative flower photographs which she practically invented, writes in the " Gentlewoman " on photographing cats. She says: "If possible, use a white background—a sheet hung over a clothes horse will do —and let the cat stand on something white—puss does not score a piece of flannelette. This isolates the figure, and prevents it in any way getting mixed np with its background or surroundings. A cat photographed like this against white comes out in a photograph more like a very clever drawing, for the camera is an excellent draughtsman, if only we will use his powers. If our cat model is taken with cushion, chair, etc., they are mado of equal importance, and all the beautiful lines ot the cat are lost."

One constantly feels that the real possibilities of velox aud similar gaslight papers have never been realised, and that it yet remains for someone to come forward and demonstrate that it is not the fault of gaslight development papers but of those who use them that prints are so often lacking in depth and solid fn the shadows and harsh in high lights. (Moreover, the proper use of one of the newer sulphiding methods of toning may be counted on to make a vast difference. Amongst professional demonstrators no one, perhaps, has been more successful in showing the working of such toning mixtures as Mr Harry Wade, who suggests a modification of the original Ulake-Smith formula. It is as follows: A.—Potassium ferncyanide, loz; potassium bromide, 30gr; water, 9oz. B.— Sodium sulphide, loz; water, 15oz. This solution will keep well, and is easy to prepare. The procedure is very simple and exceedingly fascinating. Tho prints, which should be washed till free from hypo, a're placed in the bleachiinybath. In a minute or two the image is almost bleached away. Now rinse in water, and place in the sulphide-bath. The prints immediately assume a rich sepia tone, and a few minutes' washing completes the process.

It is curious that, although there arc ample evidences that the origin of the combined, toning and fixing bath, the " Sel d'Or," gave permanent results, endeavours have been made to improve upon the old formula and then cast aspersions on its reputation for permanence. There aro abundant proofs that the simple hypo and gold bath may be relied on, existing prints toned many years ago remaining to this day of fine velvety black, the paper itself only having discoloured and become yellow. It is true that many have found this not to bo the case, but it is safe to say that the fault lay in the operation, not in the method. A given quantity of gold will only tone a given quantity of prints, but after the gold has become exhausted the solution will still continue to give fine tones of certain silver sulphides, and it is they that are not stable. So long as only the proper quantity of prints are toned, their stability may be depended on. Such good authorities as Dr John Niool and Mr i'. C. Beach have said that the " combined bath", is practically " sel d'or," and that prints toned by it are as permanent as those toned in separate solutions. The formula generally given is: Chloride of gold, 1 grain; carbonate of soda, 20 grains; hyposulphite of soda, i ounces; water, 20 ounces. Add the gold and carbonate of 60<Ja mixed together to the hyposulphite solution, stirring meanwhile.

j Whilst there is no reason why any degree of density or of thinness in a negative should not be 6ecnred with any developer, there seem to be some which more easily tend ono way or the other when in the hands of the inexperienced, and the large proportion of prints possessing excessive contrast which is seen 'in most amateurs' collections may often be traced to the use of hydroquinone developer not fully understood and hence not properly under control. An excellent developer which is more likely to give those thin, dclicato tones which modern taste demands is as follows: Sulphite of soda, 6U grains; carbonate of soda (not bicarbonate), 45 grains; alleging that it yields better prints hecause printing is slower, hut in a lantern slide it is a very difierent matter, cikonogen, 15 grains; water, is advisable to add about two drops of a 10 per cent, solution of 'bromide of potassium to each ounce of developer.

Yellow stain on a negative matters little so long as it is uniform; indeed, some printers prefer a stained negative, and a good stain remover is the following: Alum, ioz; sulphate of iron, joz; citric acid, joz; water, 12 oz. Allow the slide to soak in the solution for about twenty minutes. The solution will keep for a long time, and may be used for negatives.

i Demonstrating the bromide process some little time ago, .Mr H. C. Bird pointed out Eh-at correct exposure and correct development constitute such ex- ■ posure to light under a negative that | with a normal developer the image is developed to its utmost capacity, and however prolonged the immersion within reason the print should develop no further, but he continued: " Development with a normal developer in this manner is only to be recommended when a plain, straightfordward enlargement is required. If it is wished to control or modify the print in places a dilute developer should he used. It will take much longer to complete development or attain the limit of reduction, but it will he arrived at nevertheless, and the intensity of the shadows will he the same as if a normal developer had been used. By developing in this manner one can restrain with potassium bromide, or ac celerate with a stronger solution the parts which are to be controlled, just infancy diotates."

A good diulted developer such as that suggested would Ik- (he following: Amidol. 25gr; sodium sulphite. 32-)gr: Hater, lOoz. This is a normal solution, and should only ho used when one is certain of correct exposure. It -should b (! diluted further to a hulk of 20oz. Ir will bo noticed that there is no potassium bromide in this formula, and it is not at all necessary. It can he used during development to paint, on parts of the image it is required to keep hack', and a 10 per cent, solution is a most powerful rcstrainer with bromide paper.