Volltext Seite (XML)
458 THE PHOTOGRAPHIC NEWS. [June 26, 1891. curtains. A time of day should be chosen when actual sunlight cannot enter the room, for a patch of bright light falling in one particular place is sure to make an unpleasant flaw in the picture. In London, and other places where the houses are near together, it is generally necessary to give an exposure of nearly half- an-hour ; but, of course, exceptional circumstances may modify this to a considerable extent. Not long ago we were shown two photographs of the interior of a church which were as perfect as could be wished. Such photographs are too often of the “ chalk and soot ” variety—the soot being represented in the black roof and pews, and the chalk by the win dows, which usually spreads its whiteness by halation far beyond the limits of the window frame. These particular photographs were simply perfect. There was not only no halation from the east end window, but every detail in the stained glass pictures could be made out. More than this, the frescoes painted at each side of the window on the church wall were also rich in detail. How wasthis fine result achieved ? was our enquiry. Were the plates backed, or were films used ? The photographer used ordinary plates, un prepared in any way, and his success was mainly due to the simple expedient of having the east window of the church covered during the major part of the expo sure. This is how it was done. The camera was carefully laid in position and focussed, a plate inserted, and an exposure of ten seconds given, after which the lens was capped. The window was now covered up, outside the building, with a baize carpet, reared on two uprights and a cross-piece, the arrangement being easily handled by a couple of men. The photographer now uncapped his lens once more, and gave an exposure of ten minutes. At the end of this time he put a fresh plate in the camera, and once more gave an ex posure of ten minutes, and again capped the lens. It now only remained to take away the screen from the window, and to give a supplemental exposure of ten sconds, and two well-exposed and perfect negatives were the ultimate result. The same artifice can be adopted in most cases where it is desirable or necessary to include a window in an interior photograph, and it is by taking the trouble to make use of such expedients that the excellent workman is recognised. The Dowager Crown Princess the Archduchess Stephanie recently went to the Austrian Museum to inspect the In ternational Exhibition of Artistic Photographers in Vienna. She was received by the director of the Museum, the president, and vice-president of the Club. First she looked at the photo graphs exhibited by the Archduchess Maria Theresa, the Patroness of the Exhibition, the Grand Duke of Tuscany, the Princess of Wales, and Count Henry Bardi. She told the gentle men accompanying her that she occupies herself with photo graphy a good deal for making sketches for pictures afterwards. She has taken many photographs at Venice and Naples. It was the seascapes which especially pleased her, and particularly the picture of Jersey, by A. K. Dresser, which work of art she desires to possess. The president will take the steps necessary for procuring her the picture. After staying nearly an hour and a half, her Imperial Highness took leave' after again expressing her appreciation.—From the Neue Freie Presse. THE FABRICATION OF PHOTOGRAPHERS’ VARNISHES* BY H. C. STANDAGE. Colouring of Varnishes.—Sometimes it is necessary to give varnishes a certain colour, as, for example, a good lac varnish for lacquering brass-work. In such cases colouring substances that are soluble in alcohol are used. It is not necessary in these pages to give details for pro ducing such coloured varnishes; they are not much used in photographers’ work. But a few lines as to the best way to colour a varnish will be acceptable to some photo grapher who wishes to renovate the appearance of his camera, be it the metal work, mahogany frame, or leather bellows. The suitable colouring material should be dissolved in alcohol, or a tinctorial extract made therewith ; this should be filtered, and then this extract should be applied to the varnish. After the entire process of decolourising and filtering is finished, the extract should be as concentrated as possible, and enough of this saturated solution added to the fat varnish to produce the desired shade of colour. As a considerable quantity of the solution of many colouring substances has often to be taken for the purpose, it might be the case that, in consequence of this, the varnish would turn out too thin. This must, therefore, be taken into consideration, and the varnish must be made somewhat more viscid. When aniline colours are used, no attention need be paid to a possible thinning of the varnish in consequence of the addition of the solution of colouring matter, as these colours dissolve evenly, and are very productive in depth of colour. Recipes and Directions for Preparing Varnishes.—Too frequently varnishes are empirically made, which is a most unsatisfactory way, as no haphazard work ever turns out satisfactorily. It is absolutely necessary to know for what purpose the varnish is to be used before a properly made product can be obtained. The different properties—as that of great hardness, which is always combined with a certain degree of brittleness, or elasticity and pliancy— can only be obtained by using different kinds of resin. The hard resins, like amber and copal, will produce very glossy, but also quite Irittle, varnishes; whereas sandarac, mastic, elemi, and Venetian turpentine possess the property of making varnishes more pliant and tenacious. The little variety of purposes, however, which the photographer uses varnish for restricts this quality to a few. The lacs and sandarac resin are the two chief ingredients used in photographic varnishes. The first comprises several varieties—ruby lac, shellac, seed-lac, and stick-lac. The first is the natural product, while the second and third have been manipulated to give them less colour, so as to suit them for various purposes. The first, or ruby lac, is the best for the photographer to use in making varnishes, as the bleached kinds contain traces of the acids, &c., that have been used in the bleaching process. If large quantities of the varnish are required, it is as well to keep a stock of dissolved resin, and diluting this to the proper consistency as occasion requires—e. g., take of— Ruby shellac 1. 1 part Alcohol (90 per cent, strength) 5 parts Allow the resin to digest by frequent shakings or stirrings, and then set aside for several weeks to settle. This will * Continued from page 451.