Wednesday, June 11, 2008

EX CATHEDRA: Phase and Change; Strong v. Saturated Solutions; Commercial Flower Photography; Field Camera Bellows.

Phase and Change.

           While much is being talked of reconstruction on the grand scale, in the comparatively small field of photography we see things changing as the inevitable result of the circumstances of the time. The balance between the supply of and demand for labour - if that can be called a balance which a few months ago showed the latter to be immensely in excess of the former has been disturbed, and signs are plainly discernible of a reversion to the pre-war conditions under which the supply, or, at any rate, the publicly offered supply, was greater than the demand. It is easy to understand that the progress of demobilization in conjunction with the new labour which has been recruited daring the war should tend towards this condition in the ranks of photographic assistants. And the same thing is observable in respect to the firms or individuals who cater for photographers trade work. Such who have come into existence during the war now find themselves in competition with the demobilized ones who formerly had their established circle of customers, and are now taking active steps to recover their business. The circumstance provides a caution to those who may be thinking of purchasing a war-created business of this kind. A connection is difficultly held, and from several motives customers will be likely to return to those who previously had their patronage. The difficulties of supply, and, in many cases, the lower quality of work during the war period are factors which will operate in the direction of restoring custom to those who previously had it, and for this reason a business which is no more than two or three years old becomes a somewhat speculative proposition.

Strong v. Saturated Solutions.

           The keeping of certain chemicals saturated solutions is a recommendation which comes from the old days of photography when workers had a nodding acquaintance with practical chemical operations. At the present time, when such knowledge is the possession of a very small minority, the practice may lead to a degree of error which may not be suspected by the individual worker. Few will take the trouble to test the temperature of a saturated solution or to make certain that it is saturated at that temperature. And even if that is done, an awkward calculation is necessary in order to discover the quantity of solid chemical which a given volume of the solution represents. On these accounts it is a much better plan, we think, to sacrifice a measure of the concentration afforded by a saturated solution and to obtain in exchange the certainty of constant strength and the convenience of translating from solution to solid. To put this idea into a concrete shape, a saturated solution of hypo is one which varies greatly in strength according to the temperature, and at any given temperature represents per unit volume an odd weight of the chemical. A much more satisfactory and convenient plan of keeping hypo in concentrated solution is to dissolve the crystals in water and make up to a volume corresponding with twice the weight for example, 1 lb. of hypo dissolved in water to form a total bulk of 32 ozs. One ounce of hypo is then contained in every two ounces of the solution and the making up of fixing baths of any required strength becomes the simplest of arithmetical calculations. The same plan may be adopted for less soluble substances, choosing a ratio of 1:3 or 1:4 in place of the 1:2 which is possible only for such extremely soluble substances as hypo, potassium carbonate, and a few others.

Commercial Flower Photography.

           One of the most difficult branches of commercial photography is the portrayal of flowers, fruit, or vegetables for catalogue illustration, yet it is work that is frequently in demand. A good knowledge of florists, flowers and horticulture generally will go far to helping the operator in emphasizing just those points that the grower or advertiser wishes to put forward to his public. Perhaps our meaning may be the more plain if we give a simple illustration, taking the case of that popular flower the sweet pea, one, which it may be added is constantly being improved by various growers who are rapidly coming to see that one of the most direct, simple and effective methods of advertising the value of their new varieties and bringing their good points before flower-loving connoisseurs is a good photograph of a perfect bloom. Among the points looked for in the perfect sweet pea are the number of flowers that can be grown upon a single stem, their spacing upon the stalk, the length of the latter, a most important point, the size of the individual blossoms, and in connection with this an absence of what is technically termed "coarseness," and lastly the colour of the flowers. If a photograph of a perfect bloom selected at some trouble by a fastidious grower is to be a success then it will have to be something more than an ordinary hit or miss photograph of the bloom, and it will need to be arranged so that the points of the flower are shown to their best advantage. Thus the adjustment of the bloom in its holder or vase is important, likewise the position from which the picture is taken, and the rendering of its texture. In the case of vases of flowers, much the same rules will have to be followed as in the case of single specimens: nothing in the way of a "bunchy" arrangement is to be permitted. Backgrounds are best made of large sheets of mounting card of various colours, and these may also be employed for growing plants out of doors in isolating the subject from its background. Upon the technical side little need be said. An ordinary field outfit having long extension and a good lens of fairly long focus is as good an equipment as can be desired, since, except in the case of flowers growing outside, speed is not of importance. Of course, panchromatic plates and a set of screens are to be regarded as absolutely essential in order to secure correct colour rendering. A thin negative having abundant detail is best, those obtained by the tank method being highly satisfactory. It is becoming realised that a photograph is more satisfactory than one of the best drawings; colour photography is likely to popularise this branch still further, and commercial photographers should take full advantage of the demand.

Field Camera Bellows.

           The modern field camera is locked upon, and justifiably so, as an instrument of precision, and in many ways it is difficult to see how the standard design can be improved. There is one point, however, that is frequently overlooked by designers and that is the importance of fitting their instruments with bellows of sufficient width. Not only do wide bellows avoid trouble due to reflected light from their inner folds, but also it is next to impossible when using wide angle lenses of short focus to avoid some "cut off" of the image on the plate by the edges of the bellows, particularly when these are made to give a long extension. This form of trouble is the more likely to be met with in the conical bellows form than when the instrument has parallel bellows. For the latter type we must confess we have a preference, but even when conical bellows are in use there is no reason why the maker should not fit them of sufficient size to prevent the trouble referred to. Some cameras that we have seen leave much to be desired in the size of their bellows, and we can call to mind one of our own instruments that could never be used with success for wide angle work for this reason. Such a fault in an otherwise excellent design is spoiling the ship for ha'porth o' tar. When the bellows are made for long extension there is often a tendency for them to “cut off” part of the image when used at a shorter extension, and for this a loop of elastic is sometimes fitted to the top of the bellows in order to draw away the extra folds from the line of rays thrown by the lens. We have found in practice that this plan is not very satisfactory, and have supplemented the loop with two more, one at each side, which are attached to the nuts holding the swing front. In this way the extraneous folds are drawn entirely out of the way. When old bellows are inclined to sag in the middle at a long extension, a couple of loops of extra length attached in the same way will go far to overcome the trouble.

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