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. 444.—March 8,1867. CONTENTS. PAGE Permanent Photographs on Canvas 109 Critical Notices 110 A Simple Collodion Film. By J. Spiller Ill On the Amount of Silver Absorbed in Sensitizing Paper. By F. 112 The Effects of Solar Action upon Glass 112 On the Employment of Blue Glass in Photography. By M. McA. Gaudin 113 M. Negre’s Process of Photo-Engraving 114 Lecture on Photography 114 Nitro-Gelatine Developer. By Prof. 115 PAG• Surveying by Photography. By B. Smith Lyman 115 Transparent Negative Holders. By Prof. Towler 116 Gelatine in the Iron Developer. By Johannes Bienert 117 Recent Patents 117 Proceedings of Societies—American Photographical Society ... 118 Correspondence—Selling Secret Processes—Col. Baratti’s Photo Plastic Process, etc. — Photographs in Oil Colours— Mr. Young’s Washing Machine 118 Talk in the Studio 120 To Correspondents 120 PERMANENT PHOTOGRAPHS ON CANVAS. A arErnOD of successfully producing a photographic portrait on canvas has repeatedly been sought, to form a satisfactory basis for an oil painting. Objections have, by some, been raised at the outset, on the ground that canvas interposed several difficulties absent in paper, without offering any special advantages. The texture and grain of canvas are alleged by many painters to possess advantages, both in being pleasant to work upon and yielding an effective result. To this it has been answered that some of the finest pictures have been painted on panel, and on other substances not having grain or texture ; and, further, that the effect of the canvas surface may be obtained by printing on thin paper, and mounting this on canvas. Without here discussing, however, the question, the fact remains that many painters prefer to work on canvas, and hence the importance of a method of obtaining a photographic image on this material. Various silver processes have been worked with more or less success; that discovered and described in our pages by the “ Photographer’s Assistant ” being, perhaps, at once the simplest and most efficient. But it is evident that if silver processes, being of uncertain permanence, are unsatis factory for producing plain photographs, they are, d fortiori, unsuitable for producing bases for the work of the painter, often necessarily more costly than the photograph itself. Hence the importance of a method of printing upon canvas by some permanent process. Mr. J. T. Lucas sends us, with a letter, which appears on another page, an example of printing upon the ordinary prepared canvas of the painter, upon which a very thin coating of bitumen of Juda has been applied. This substance is, as most photographers are aware, sensitive to the action of light, which renders it, wherever it acts, insoluble in its usual menstrua. The first fixed photographs of which we have record were produced by M. Nicephore de Niepce by means of this substance, and it has been used in various photographic processes since. Mr. Lucas found difficulties in using it, and abandoned his own experiments in view of the patent process to which he refers in his letter. Nevertheless, the result ho encloses to us is sufficiently interesting to be worth a little considera tion. The imago is a brown or bistre tint, with a slight inclination to citrine. It consists chiefly of deep shadows and lights, but is not without some indications of half-tone. The asphaltum forming the image is not insoluble in benzol, which would readily remove the whole image. We can readily conceive that, by the method employed, an image of considerable value to the oil painter might bo produced, supplying the drawing, which, although without much detail, might frequently be found useful. An important question here arises, however, in reference to the permanency, in oil painting, of bitumen itself. Most experienced painters object to its use as a pigment, notwith standing its valuable properties of transparency and ren- ness of colour, because of two fatal defects : it gradually becomes blacker, and it cracks. We recently examined an interesting group, painted less than twenty years ago, and which, we are assured, at that time was very brilliant in colour. Asphaltum was, however, unfortunately used freely in the glazings, and it is now little more than a smoky looking black mass. Many of the excellent pictures of painters of the last generation are now reticulated with cracks, which are, in many cases, traceable to the use of bitumen. We recently had a conversation with a popular painter, whose works generally occupy a position of honour on the walls of the Academy and other exhibitions, in which we asked his opinion on the subject. It was tersely given in these words : “No honest painter will use bitumen.” If this be the case, the substance, which cannot, with propriety, be used even in glazings, would scarcely be a suitable basis for the whole painting. How far the same arguments would apply to the patent printing-ink process, in which bitumen is only employed in comparatively small proportion as the sensitive agent, not as the sole colouring matter, we cannot say. Much will depend, probably, on the amount used; and the question will be better determined by time and experi ment than by conjecture. Mr. Lucas (whose knowledge of painting entitles his opinion to weight) doubtless has considered the subject, and appears satisfied. He also seems satisfied as to the safety of an image transferred to canvas. On this point we should have been disposed to have considerable doubt ourselves. We should have feared that the lack of homogeneity between the surface of the prepared canvas and the material used in transferring would have tended to the eventual exfoliating of the picture, and rendered it unsafe as a basis for a valu able painting. The chief objection that has ever been raised in. reference to Swan’s carbon prints has been on the possi bility of the image splitting off the paper on which it rests after its final transfer. In this case, the image is transferred, by means of gelatine, to a surface sized with a similar mate rial, considerable pressure being used to secure a perfect adhesion of the two surfaces, and the insolubility of the transferring medium being secured by a subsequent opera tion. Here, therefore, there are tolerably sure means em ployed to prevent risk. We should doubt the absolute security of a transfer to canvas, effected in the same way. Possibly, where the transferring medium is of an oily or resinous nature—as in the printing-ink process—the image transferred to canvas may suffer less risk of cracking or exfoliation. On this subject Mr. Lucas tells us that he does not fear cracking. Ho thinks that the analogy afforded by the method of removing old paintings from a canvas that is rotten or injured to a new one, gives satisfactory hope that the transferred images will be safe. In the method of restoring old paintings just referred to, a succession of sheets