The photographic news

• Bandzählung: 11.1867
• Erscheinungsdatum: 1867
• Sprache: Englisch
• Signatur: F 135
• Vorlage: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: Hochschule für Grafik und Buchkunst Leipzig
• Digitalisat: SLUB Dresden
• Rechtehinweis: Public Domain Mark 1.0
• URN: urn:nbn:de:bsz:14-db-id1780948042-186700008
• PURL: http://digital.slub-dresden.de/id1780948042-18670000
• OAI: oai:de:slub-dresden:db:id-1780948042-18670000
• Sammlungen: LDP: Historische Bestände der Hochschule für Grafik und Buchkunst Leipzig
• Sammlungen: Fotografie
• Strukturtyp: Band

• Digitalisat: SLUB Dresden
• Strukturtyp: Ausgabe

THE PHOTOGRAPHIC NEWS. Vol. XI. No. 473.—September 27, 1867. CONTENTS. PAGE Retouching Negatives with Lead-Pencil 461 Substitute for Ground Glass in Studios 461 Another New Dry Process 462 Foreign Miscellanea 462 The Persistent Activity of Light 463 The Meeting of the British Association at Dundee 465 A Few Hints to Photographers and Dealers. By a Practical Man 464 The Reason Why. By the Photographer’s Assistant 461 page Permanent Aniline Colours for Tinting Photographs. By J. G rassho II - 465 Reports on Photography at the Paris Exhibition 466 A New Fact Relating to Binocular Vision. By A. Claudet, F.R.S 468 Photography on Canvas. By A. J. Drummond 470 Organic Matter in the Developer and Collodion. By J. Milton Sanders, M.D., LL D 471 Talk in the Studio 471 To Correspondents 472 RETOUCHING NEGATIVES WITH LEAD-PENCIL. Since we published a description of a mode of retouching negatives with lead-pencil, giving it publicity for the first time in this country, we have had various communications on the subject, describing somewhat contradictory results. One of the most skilful and successful of provincial portrait ists says : “ The plan has been most valuable to me ; I con sider that this hint alone is fully worth all the subscriptions I have paid for my News from the first.” From some others we have received good examples of the results they have obtained from negatives retouched in this manner ; and from some we have received the information that they could make nothing of the method suggested. If they attempted to work upon the unvarnished film, there was constant risk, with the utmost care, of scratching the collodion. If they attempted to work on the varnished film, it afforded no tooth for the pencil, and it was impossible to secure results of any printing value. In our own experiments we have found that a B B, or BBB pencil, or a crayon of lithographic chalk, or an " eyebrow pencil,” sold by perfumers, would bite sufiiciently on the varnished surface of any of our negatives; but we can readily conceive that, where a very glassy surface is ob tained by using a thick varnish and great heat, it may be difficult to work with any of the pencils wo have tried. In our own practice, whilst using a spirit varnish, we avoid great heat, and so obtain a surface, not chilled certainly, but without the extremely glassy effect which great heat and a strong varnish yield. A friend has recently called our attention to the practice common in France, where retouching is commonly and suc cessfully practised, by which all the difficulty of using the pencil is removed, a surface being obtained which permits the utmost freedom in working, without difficulty in the manipulation, or risk of scratching the film. The application to the film of a dilute solution of gum arabic removes all the difficulty. After the negative is fixed and washed, but before it is dried, its surface is flooded with a solution of gum arabic sufficiently dilute to dry without leaving a palpably glassy surface. This solution permeates the film, which, on drying, is hardened and protected by it, so that there is little risk of scratching it with the pencil, and, at the same time, a surface is obtained on which the pencil bites as readily as on paper, and permits the full exercise of as much skill as the manipulator may possess in hatching or stippling, so as to introduce or strengthen reflected lights in dark shadows, and give more intensity to half-lights or high lights which are insufficiently pronounced in the negative. We are not now discussing the propriety of retouching negatives. We have before affirmed a con viction that wherever the result is good the means are justifiable. Our object is now simply to place within the reach of those anxious to produce the effect of finish and resemblance to a good engraving, which many of our readers have admired in continental photographs, the means of securing similar results ; and this is found in the negatives treated with gum and worked on with a good blacklead pencil. After this retouching the negative is, of course, varnished. We do not know of any evil results which follow the use of gum; but it has the advantage of preserving the film from the risk of solution by the varnish, or of splitting in drying should the plate have been damp or dirty and the intensifying prolonged. o SUBSTITUTE FOR GROUND GLASS IN STUDIOS. In studios built with an aspect which, during certain hours of the day, the entrance of sunlight is inevitable, an efficient means of diffusing the direct rays without shutting out too much light is of considerable importance. Ground glass, besides being costly, obstructs a considerable amount of light. Tracing-cloth or tracing-linen is an excellent material, but it gets dirty and discoloured, and so impedes the passage of light unnecessarily. Tissue paper has many of the same disadvantages. Our attention has recently been called by Mr. Blanchard to the superiority to any other material for this purpose of a coating of starch applied to the glass. A solution of starch has before been recommended for producing a substi tute for ground glass for the focussing-screen ; but we have not before heard of its application to the windows of the studio, and as the result is, we are told—and we can readily believe it—much superior to other appliances for the same purpose, it is well worth noting. The solution should be very thin, and applied, slightly warm, with a brush, which is very easily done. When dry it is very transparent, and obstructs but little light; but it breaks and diffuses the direct rays of sunlight sufficiently. When soiled or scratched it may be at once removed with a moist sponge. It will bo seen that it is cheaper and more easily applied and removed than the various other means which have been suggested for securing the same end. Since writing Mr. Blanchard’s suggestion, we find a similar hint by Mr. Grasshoff in the Mittheilungen, who speaks of the value of starch for this purpose.